THE AVIATOR 





Class 
Book. 



*J 






Gopyriglrt>J?. 



C.QFHUGHT DEPOSITS 



THE AVIATOR 




Copyright by Underwood & Underwood, N. Y. 

The Italian Alps as the Aviator Sees Them 

It is almost impossible to tell the direction of the grades in 

the road at this height. 



THE AVIATOR 



BY 

HENRY C. McCOMAS 

Professor in the Division of Science at Princeton University 
Formerly Captain, San. C. t U. S. Army, at the Research Labora- 
tory, Hazelhurst Field, Mineola, L. I., N. Y. 




NEW YORK 
E. P. DUTTON & COMPANY 

681 Fifth Avenue 



Copyright, 1922, 
BY E. P. DUTTON & COMPANY 

All Rights Reserved 






PRINTED IN THE UNITED STATES OF AMERICA 



22 jcc 



C1A690353 



9tf 

THE MEN WHO 

WON THEIR WINGS 

BUT 

WHO DID NOT GET ACROSS 



CONTENTS 

CHAPTER PAGE 

I. The Aviator as a Machine ...',. i 

II. Nerve and Nerves 8 

III. Controlling the Plane 33 

IV. The Sense of Motion and Balance . 59 
V. Vision in the Air 86 

VI. Other Senses 114 

VII. The Feel of the Ship 122 

VIII. Oxygen and Efficiency 140 

IX. Doing Stunts 165 

X. Selecting the Aviator 176 

XI. Types of Airmen . . t . . . . .188 

XII. The Pilot as a Personality .... 197 



ILLUSTRATIONS 

The Italian Alps as the Aviator Sees Them Frontispiece 
Flying Reptile, Restored from Fossil Remains Page 2 



A Type of German Monoplane 
The Controls of the Airplane . 



Instruments for Detecting the Lateral and 
Longitudinal Movements of the Airplane 

Organs of Motion and Balance .... 

The Simplest Organ for Giving the Sensations 
of Motion and Balance + 

In This Position the Vertical Canals Are Af- 
fected by the Rotation of the Chair . 

A Series of Steep Banks in a Long Spiral Will 
Affect the Vertical Canals .... 

The Frame of a Ruggles Orientator . 

Muscles Controlling Eye Movements . 

Front of the Eye Viewed from Within . 



4 
4i 

61 
63 

67 

73 

77 
84 
88 

96 



Niagara Falls from an Airplane at 350 Feet 

Facing page 108 

Notes Made at the 20,000 Feet Altitude . Page 160 



INTRODUCTION 

After the Wright brothers hit upon the 
principle of controlling a gliding machine, 
the progress in aviation was astonishing. 
Their discovery came at a time when the ex- 
perience in manufacturing automobiles was 
available for the development of the air- 
plane. Already, the solution of many of the 
problems of light and powerful motors, metal 
alloys, ignition and carburetion were under 
way. Before the war began, the airplane 
was a practical machine. During the war, 
all the great nations developed the invention 
with a vigor and ingenuity that no other in- 
vention ever received in so short a time. As 
a result, the airplane is a highly perfected 
machine; each inch of its surface, from the 

pitch of the propeller to the lines of the rud- 

. 



xii INTRODUCTION 

der, give evidence of the study put upon it 
So absorbing was this work that the other 
factor in aviation, the aviator, came in for 
comparatively little scientific attention. True, 
he was featured in fiction and romance, but 
that did not help his flying. It became evi- 
dent, as the war continued, that in the art of 
aviation the operator was quite as important 
as his instrument. Then each nation under- 
took the study of her airmen; not with the 
spirit, nor with the assurance that her en- 
gineers studied the planes, but in a hesitating 
and apologetic way. Nevertheless, it became 
apparent to every one interested in aviation 
that the aviator should be understood as well 
as the airplane. To accomplish this, the ma- 
chinery governing his conduct must be studied 
as thoroughly as possible. Here again, avia- 
tion is fortunate in being born at a time when 
the sciences of psychology, physiology and bi- 
ology have accumulated a great deal of infor- 
mation that bears upon the problems to be 






INTRODUCTION xiii 

solved. To bring some of this material to the 
lovers of aviation and to put it in readable 
form, is the purpose of this book. 

Henry C. McComas. 

Princeton University, 
June 23, IQ22 



THE AVIATOR 



THE AVIATOR 

CHAPTER I 
THE AVIATOR AS A MACHINE 

It IS not uncommon for the pilot to think 
of the airplane as human, with all of the ec- 
centricities of human nature. The tempera- 
mental peculiarities of a gas engine are about 
as unpredictable as the moods of a coquette. 
No wonder the mechanic calls it "she." He 
finds the evidences of a personality there. 
Turn this idea upside down and we have a 
new idea. Instead of thinking of the plane 
as a person, think of the pilot as a machine! 

He is a machine. The system of levers 
which runs from the ailerons does not stop 
until it reaches his shoulder socket. The 
cords which swing the rudder continue until 
they terminate in the pilot's thighs. Both 



2 THE AVIATOR 

machines suffer from cold, from the changes 
in the air densities, from prolonged flying and 
a number of other ills. They are not two ma- 
chines, they are one. The success of the flight 
depends upon the combined action of the pair. 
The airplane was designed to do its work 
in the air, but the pilot was designed by nature 
to do his work on solid earth. A comparison 
of the type of machine Nature has produced 




Flying Reptile, Restored from Fossil Remains 
One of Nature's earliest experiments in aviation. 

to navigate the air with the type evolved to 
move upon the ground shows some very im- 
portant differences in design. Several mil- 
lion years ago Nature began experimenting 
with air machines. At that time there were a 



AVIATOR AS A MACHINE 3 

number of light, agile reptiles who were being 
badly crowded by the increase of other ani- 
mals. In their leaps to escape the monsters 
of the swamps, those who were lightest and 
who had the spreading membranes, which 
enabled some creatures to glide, were the ones 
to survive. Probably the first designs by Na- 
ture paralleled those of man, and were glid- 
ing machines. Then improvements were 
made. One of the first models known repre- 
sents a pretty good type of air machine. The 
long rudder-like tail-piece probably served 
both as a rudder and an elevator. Later 
models shortened this structure and restricted 
its purpose. Our aeronautical problems were 
met ages before man appeared and Nature be- 
gan trying out methods of getting more power 
in the engine and of lessening the body weight. 
Shoulder girdles were strengthened and hol- 
low bones with pneumatic attachments were 
attempted; and met with success. Such birds 
as the albatross, which is a powerful flier, 
have the pneumatic system perfected. The 



THE AVIATOR 



hollow bones are connected with aircells, so 
that the air entering the lungs may also reach 
the bone marrow. Moreover, the problem of 
stream-lining was early taken up and solved 




A Type of German Monoplane 

Showing ingenious efforts to take hints from Nature's 
experiments. 

by Nature in the graceful tapering lines of 
so many types of birds. Compare the rep- 



AVIATOR AS A MACHINE 5 

tilian head in the picture with the smooth 
lines of any modern bird. Notice the be- 
ginnings of stream-lining in the body form. 
German astuteness early saw the numerous 
hints Nature had for those who were making 
heavier-than-air flying machines and the Ger- 
man airplanes are more closely modelled 
along the lines of bird forms than those of 
any other nation. 

Not only is the gross structure of Nature's 
flying machines unlike that of the types which 
move on land, but there are many little re- 
finements in structure, which perfect the fly- 
ing machine. For example, the eye of the 
bird is brought against a severe pressure in 
the air when it flies at high speed. Nature 
strengthens the eyeball and supplies a third 
lid. A differentiation is made in the eyes of 
those doing night work. A higher body tem- 
perature and a covering of feathers give the 
bird a natural advantage no human ingenuity 
has matched. No fore-and-aft level, or side 
slip device can make the human flier fly as 



6 THE AVIATOR 

the bird does. No one ever saw a bird fly out 
of a cloud upside down! No compass will 
ever take a man across a continent as the in- 
stinct takes the bird. By instinct the bird 
takes off from the ground into the wind; by 
instinct they fly in a squadron formation, so 
that they do not interfere with each other. No 
such endowments are 'given man. He must 
use intelligence where his aerial competitors 
use native instinct. 

In short, Nature has made one type of ma- 
chine for moving in the air, another for mov- 
ing on the surface of the earth. When the 
latter type is put into the natural element of 
the former, certain difficulties arise. What 
these are and how we may meet them are the 
subject matter of this book. 

At the outset, we must consider the very 
common difficulty which besets the flier. Na- 
ture made man with a certain kind of nervous 
system. It was evolved to make a man feel 
and act in a certain way whenever he en- 
counters a sudden danger. Can this sort of 



AVIATOR AS A MACHINE 7 

behavior carry man through the perils of 
the air? Some attempt to answer that ques- 
tion appears in the chapter *on Nerve and 
Nerves. The art of flying calls for an ac- 
tivity of the brain and nervous system of a pe- 
culiar kind. This is made clear in Control- 
ling the Plane. After these chapters, the va- 
rious senses, which act as instruments to in- 
form and assist the flier, are explained and 
discussed. From that we naturally turn to 
the common enemy of both the pilot and the 
airplane, Altitude. In this study we find dif- 
ferent types of airmen and a description of 
the method of selecting aviators follows. 
Finally, some facts which find no place in the 
study of men as machines are presented in 
the concluding paragraphs on the Pilot as a 
Personality. 



CHAPTER II 

NERVE AND NERVES 

A PLANE caught fire at 2000 feet up. 
From the flying field a wonderful flight was 
witnessed between a flaming airship and a 
cool-headed cadet. He turned his ship over 
so the fierce tongues could not lick him. He 
hung from his fuselage with one hand and 
brought his machine down toward the ground 
with the other. The fire burned out. He 
sought to regain the fuselage and right 
his ship. She became unmanageable. He 
worked quickly, skillfully, intelligently. She 
plunged toward a woods. Still striving to 
steer and balance her, the pilot and the plung- 
ing, rolling ship disappeared among the trees. 

These disasters are not often discussed, 
or deplored, among the cadets. It is all in 
the day's work. But, months after the man 

8 



NERVE AND NERVES 9 

had been laid to rest and the airplane scrap 
ped, the cadets would speak of the fight. 
The way to handle a plane when she catches 
fire is a matter of technique, a scientific ques- 
tion, and it often comes up. This fight never 
received a purely technical treatment; always 
this remark entered the conversation some- 
where : "It's a shame he didn't get away with 
it, for he certainly had a nerve" 

Two friends bunked together. Both were 
making excellent headway in flying school 
work. One crashed and was killed. The 
other never flew well afterward. His land- 
ings were bad and his tight eights looked as 
though they were both "tight" and tipsy. 
He was grounded. "It was hard luck," said 
his friends. "You see it was a case of nerves." 

Nerve and nerves! The singular spells 
self-control, the plural means the opposite. 
This trick of concealing ignorance with words 
is an old one. It has its good points. When 
we come to the end of our information, it is 
convenient to give the terminal a name. 



io THE AVIATOR 

A great many people reach that place very 
quickly, when they attempt to understand 
themselves; then they find comfort in 
"Nerves." 

If we follow the line of reasoning of the 
preceding chapter, we shall soon discover 
that there is no necessity for considering a 
play on words, the final terminal, in an effort 
to understand self-control ; which is, of course, 
a form of conduct. Conduct varies in differ- 
ent animals strikingly. Compare the com- 
placency of a porcupine under all circum- 
stances, with the temperament of the jack- 
rabbit. The porcupine is so well protected 
fate cannot harm him. He saunters into camp 
unmolested by the dogs. He shows no fear of 
man. His equipment for sensing danger afar 
and for flight is not developed at all. Had 
he nothing but the rabbit's fur he would have 
to have another nervous system and another 
type of locomotion. Compare the conduct of 
such unlike creatures as an opossum and a 
fox. A danger signal near at hand paralyzes 



NERVE AND NERVES n 

the former, it galvanizes the latter into swift 
action. The same menace inspires the same 
fear in both, but the instinctive reactions are 
the opposite. An analysis of the organs and 
their functions, in these two types of animals, 
would make their conduct intelligible. In 
one we should find the excitement results in 
nerve action preventing movement, in the 
other it stimulates vigorous action. Here, 
then, is our cue. Nature has endowed differ- 
ent forms of life with different mechanisms 
for behavior in the presence of danger. Can 
we not learn something about the conduct of 
human beings, in the presence of an imminent 
peril, by a study of such mechanisms? 

The physiologists have afforded a new in- 
sight into the mysteries of human nature by a 
study of the organs and functions which op- 
erate during the stress of strong emotions. 
These organs are controlled by the nervous 
system; so it is necessary to give a brief 
sketch of the nervous machinery and the way 
it works, in order to understand such emotions 



12 



THE AVIATOR 



as fears, anxiety, dread, anger, and all the rest 
of the list which we find credited to the man 
who flies. Roughly divided, the nervous sys- 
tem may be considered as two systems; one 
has to do with the action of the person and 
the other has to do with the action of the in- 
ternal organs. The former is known as the 
central nervous system and it consists of three 
parts; (first, a set of nerves which brings im- 
pressions from all of the sense organs to 
(second) the brain and spinal cord, and 
(third) a set of nerves carrying impulses out 
from the brain and cord to the muscles and 
glands. This is the system which controls 
our conduct as we live and move among our 
fellow men and among the objects of nature. 
Closely allied to it is the autonomic nervous 
system, but its duty is the control of the vital 
organs, heart, lungs, stomach, and all the 
others. It, too, may be divided into three 
parts; first, a set of nerves which have as 
their purpose the conservation of bodily re- 
sources by controlling the supply of the juices 



NERVE AND NERVES 13 

which digest the food, by controlling the 
movements of the stomach and intestines and 
by bringing about the cooperation of other 
vital organs for the purpose of carrying on 
the upbuilding of the body. This set of 
nerves is known as the cranial. 1 A second 
set of nerves has as its purpose the excitation 
of the vital organs when they are called upon 
to do extra duty. For example, when we run 
from some dangerous object, the muscles must 
have more than their ordinary supply of fuel, 
so both heart and lungs must work more vig- 
orously. This set of nerves starts both heart 
and lungs into quickened action before we 
may begin to run. It is known as the sympa- 
thetic nervous system and is much more elab- 
orate than the cranial. Where the latter acts 
to slow the heart rate, the sympathetic system 
acts to quicken it. Moreover, it stops the ac- 
tions of the cranial nerves in secreting juices 
for digestion and in its movements of the ali- 

1 For an excellent description of the autonomic nervous system 
see Bodily Changes in Pain, Hunger, Fear and Rage, by Walter 
B. Cannon. 



i 4 THE AVIATOR 

mentary canal. All the energies of a person 
are needed in the muscles and in the heart, 
lungs and brain, when there is danger. The 
work of the stomach and intestines must stop 
while the other organs are putting forth their 
best energies to help the muscles in their 
work. This set of nerves is a sort of war de- 
partment; when there is any danger it stops 
all business which is not necessary for the 
preservation of life. A third set of nerves 
in the autonomic system is known as the sacral, 
one of its duties being the control of the sex 
organs. Between the cranial and the sacral 
lies the greater and more diffuse set of nerves 
the sympathetic, and it overrides the activities 
of both of its neighbors. 

From this sketch of the machinery, we may 
find the explanation for some of the mys- 
tifying things we have all noticed in the emo- 
tions. Each of these groups of autonomic 
nerves is accompanied in their actions by char- 
acteristic feelings, or emotions. When the 
cranial nerves are engaged in the delectable 



NERVE AND NERVES 15 

work of controlling the necessary juices for 
the digestion of a good meal, the general sense 
of well-being, which prevails makes a sharp 
contrast with the feeling of being "ill at ease" 
when anticipating some unpleasant encounter. 
The latter feeling may develop into a genuine 
fear, or even terror, then none of the complai- 
sance of well-being remains. One cannot 
even eat his food, much less enjoy it. If it 
reaches the stomach, it may be ejected, or lie 
undigested. As an experiment, an animal was 
fed and then subjected to a period of fright; 
it was observed that all movements in the 
stomach and intestines ceased. Many an avia- 
tor has made his passenger vomit from sheer 
fear. Even more conspicuous in the emo- 
tional realm are the conflicts between the 
emotions which arise from the sex life, con- 
trolled by the sacral system, and the emotions 
fear and anger, controlled by the sympathetic 
system. 

It has been found that the work of the 
sympathetic system is aided in a very remark- 



;i 6 THE AVIATOR 

able way by the secretion into the blood of 
adrenalin. Two small glands lie just back 
of the kidneys, which are known as the ad- 
renal bodies. The substance they secrete 
passes through the blood-stream to all parts of 
the body. If an animal is inoculated with 
adrenalin he shows those symptoms which ap- 
pear when the sympathetic system is arousing 
the creature to fly from some danger. The 
pupils dilate, the hair stands on end, the heart 
and breathing rates increase. A careful ex- 
periment shows that even the tired muscles 
are refreshed. Adrenalin is a sort of reserve 
corps which jumps into action the instant there 
is a danger signal. When the first set of 
nerves in the central system is affected by some 
outside danger signal, let us say a curtain on 
fire, the nerve current passes to the brain, 
arousing a conscious state. It then passes to 
the third set of central nerves and starts the 
muscles into action, but as it does this the cpn- 
scious state affects the mechanical operation of 
the nervous system. If the fire is really dan- 



NERVE AND NERVES 17 

gerous, the autonomic system is roused by the 
recognition of the danger. At once the sym- 
pathetic system quickens the heart, the breath- 
ing, stimulates the adrenal glands, the muscles 
become abnormally "irritable," the blood 
leaves the cheeks, it flows to the parte in ac- 
tion. With the general disturbance come the 
characteristic sensations which we speak of as 
the "emotion of fear," sensations from the 
heart, the stomach, the quickened breathing 
and the tension in the muscles. 

This emotion of fear and the physiological 
activities which accompany it constitute an 
instinct. An instinct is often called a racial 
habit, it is characteristic of the human race, it 
is a genuine part of human nature, it operates 
automatically; given a certain stimulus, we 
find ourselves doing certain instinctive things. 
An unexpected danger, or a sudden, violent 
pain, will start the racial habit into actions of 
the kind we have just been describing. 

Now we have the materials for explaining 
some of the mysteries of "Nerves." For ex- 



1 8 THE AVIATOR 

ample, it is a common experience in learning 
aviation to be very restless, anxious, perhaps 
thoroughly scared, during the first few trips 
when one is simply observing the ship and its 
behavior. All of these symptoms disappear at 
once as soon as one takes the wheel and the 
rudder! Instead of experiencing greater ex- 
citement and apprehension, he becomes 
calmer and feels he has better control of him- 
self. One of several reasons for this is, he is 
doing something. The whole system is pre- 
pared by the excitement of the occasion to do 
something. If these natural processes mak- 
ing for action are blocked, one has that most 
distressing experience of fighting against na- 
ture. To avoid this, many trainers have their 
men do something prior to entering a contest, 
something that enables the organs to act at 
least mildly when they are urged by Nature to 
act vigorously. It has been found that the ex- 
citement of witnessing a football game by a 
substitute player definitely increased the 
blood-sugar, which is needed for active mus- 



NERVE AND NERVES 19 

cles. The same results are found in the anx- 
iety of anticipating college examinations. 
Excitement calls for action to work it off ! 

Surely the poor mortal, who prepares for 
his first flight in an airplane and discovers 
his knees trying to beat "taps", his complex- 
ion like a flag of truce, his heart and breathing 
misbehaving and that annoying cold sweat, 
will find consolation in Physiology. No; it 
is not a "yellow streak" in his make-up, it is 
just adrenalin and a rampant sympathetic 
nervous system. Is he going to be any good 
in the air? That depends upon what his in- 
ternal machinery does when it gets into action. 
If the emotion incident to impending danger 
still arouses excessive actions in his organs, 
which his efforts do not direct and restrain he 
will be "too nervous to fly." Often a man has 
sense enough to know that his machinery, in- 
herited from his ancestors, is not dependable, 
and that he gets "rattled" when he is excited. 
Many experiences have taught him not to trust 
his instinctive actions. Such a man shows 



2o THE AVIATOR 

courage and good judgment when he leaves 
aviation alone. 

Another trick of the nerves gets its partial 
explanation here. When a beginner in swim- 
ming, rowing, fencing, or any sport is some- 
what excited by his new experience he over- 
exerts himself. His motions are too quick and 
too vigorous. If you began to sail a boat 
with a little anxiety about its performances, 
you will remember how hard it was to let the 
sheet and rudder alone after you had them set 
for a steady wind. Nature was urging ac- 
tion, your physical ship was cleared for ac- 
tion with boilers hot and steam up. Your 
teacher made you sit still. Probably you 
found compensation in squeezing the tiller 
till your hand was numb. That is what the 
beginner in the airship tends to do. The in- 
structor often casually remarks, "Don't try 
to squeeze the juice out of the stick, it's been 
seasoned." Perhaps it is as well to let the 
novice squeeze! It uses up some of that sur- 
plus energy his system is supplying and may 



NERVE AND NERVES 21 

do a little to prevent him from overworking 
his controls. 

The question naturally arises, what would 
happen if a man were kept in a state of ex- 
citement continually, or frequently, and not 
allowed the action his nerves and organs de- 
mand? The answer is given in a comparison 
of nervous troubles which afflict pilots and 
observers. The latter break down sooner and 
to a greater degree than the former. 1 The 
pilot's attention and energies are occupied 
with the ship. The observer has his mind 
freer to note the dangers of the situation. He 
must also trust the pilot for his safety. If 
there is an accident, he can do nothing. He 
must rely on his associate. His attention can- 
not be diverted from the danger to an active 
control of the plane. 

A pilot once told me that he was surprised 
to find his companion, who "had a wonderful 
nerve" give way and cry, "Oh ! God ; oh, dear 

1 Anderson, H. G., The Medical and Surgical Aspects of 
Aviation, p. 116. 



22 



THE AVIATOR 



God !" as they crashed from about a hundred 
feet. He declared he had no emotions of any 
sort, that he felt as clearheaded and had him- 
self as well under control as at any time. He 
was busy u trying to slap this planet as gently" 
as he could, and was a little surprised to hear 
his usually silent companion so vocal. 

This leads us into another phase of the sub- 
ject. When the attention is directed to the 
controls, the mind is not dwelling on the dan- 
gers. When there is no thought about danger, 
there is no anxiety. The crux of the issue is 
in the attention. When the beginner gets 
his hands on the wheel and his feet on the 
rudder, his thoughts turn to things mechanical 
and there is little room for ideas of crashes. 
This, with the efforts to control the ship, dis- 
pels the anxieties which will haunt the most 
intrepid in his trips as an observer. Indeed, 
there are many pilots, who never know a mo- 
ment's discomfort, when controlling the air- 
plane themselves, that become actually sick 
when they ride as passengers. I found in my 



NERVE AND NERVES 23 

first flights the tension of the situation relaxed 
considerably when I ceased speculating on 
landings and watched the controls, trying to 
relate movements of the stick to changes in the 
ailerons. 

Self-control, then, is the indirect result of 
control of the attention. The high-strung, 
college graduate who knows how to keep his 
mind on one line of thought and the stodgy, 
unimaginative fellow, who is never afraid, 
may both show their "nerve" in danger, one 
because he concentrates upon a certain line 
of thinking, the other because his mind is too 
inactive to entertain anything but what 
chances to occupy it at the moment. 

A man's training in control of his thinking 
is invaluable in times of danger. The abil- 
ity to concentrate is all important. Here the 
difference in the mental traits of men shows it- 
self in their conduct. 

The pa^fcof the nervous system in which 
consciousness is resident, the cortex of the 
cerebrum, is the most recent acquisition of the 



24 THE AVIATOR 

human species. It developed during the ages 
after the lower centers and the cord had 
reached their development The functions of 
the old system run back into the remote ages. 
Those of the newer are not so deep-seated, so 
fundamental. The old has to do with the 
most ancient activities, instincts for flight, or 
self-preservation and the emotions which ac- 
company them. The new has to do with con- 
scious conceptions, with the social ideals, pa- 
triotism, honor and the respect of others. It 
has been suggested that some forms of war 
neuroses arise from a conflict between these 
two parts of a man's nervous system, and their 
duties. Thus, the terrible detonations of the 
battle naturally arouse the instinct of flight — 
all living creatures possess the instinct of 
flight in the presence of very loud, or sudden, 
noises. The cries, the odors, the scenes of 
mutilations all arouse the deep instincts of es- 
cape from the imminent horrors. Against 
these impulses stand the ideals of the in- 
dividual. He thinks of the shame of flight. 



NERVE AND NERVES 25 

He resists the impulses of his nature and holds 
himself in an unnatural environment. From 
this conflict comes a nervous break-down 
which is often miscalled "shell shock." 
Among aviators this conflict often results in a 
staleness. The effort to force the brain to 
endure the long strain of flying over the ene- 
my's lines results in a loss of nerve energy. 
The brain is fagged. There is a loss of in- 
terest in everything. There is no desire to 
read, to play, or to do anything. Sleep is 
hard to win, dreams are excessive and dis- 
tressing. Occasionally delusions appear and 
haunt the listless wretch. Persistent ideas, or 
insistent fears beset him. He has overtaxed 
the most finely developed and adjusted part of 
his nervous system. If he, or his officers, ig- 
nore these protests of nature and force the vic- 
tim to continue his work, he is surely destined 
to disaster. 

One of the most pathetic notes I have en- 
tered into my records is a story of an Ameri- 
can aviator, as it was told me by his two chums. 



26 THE AVIATOR 

The man was a college athlete of the best 
type, strong, alert, full of pluck and ingenuity. 
He kept in the air too long, he grew stale. 
Then something happened that never oc- 
curred before in all his many encounters, an 
opponent crept upon him unawares. His 
chums declared the Hun did not get him, it 
was the long hours in the air that killed their 
friend, plus his determination to make his 
constitution bear the unnatural strain. In 
trying to select aviators, one of the first in- 
terests was whether he had the nervous sys- 
tem to stand the strain of great excitement and 
whether he could keep it in control. 

As might well be expected there are some 
men who give way under the strain more 
easily than others. Dr. Gotch * found that 
167 out of 200 patients at the Royal Air Force 
Hospital, Hempstead, gave evidence of nerv- 
ous instability either on the mother's or 
father's side of the family, or on both sides. 
"The worst cases almost invariably showed 

1 Op. cit. p. 112. 



NERVE AND NERVES 27 

some." Dr. Gotch followed up his patients' 
family histories, inquiring into their national- 
ities "particularly as to any Celtic or Hebrew 
blood, " also noting the cases of alcoholism, of 
eccentricities, the "attitude toward worries 
and troubles of all kind." Slight defects in 
the nervous organization of a man may never 
show in ordinary -civil life. He may live his 
three score and ten years quite like anyone 
else, "but in the case of the flying officer this 
is different. The experiences he daily under- 
goes whilst on war-flying involve the greatest 
strain on his nervous system that is possible in 
any 'human being, and it is reasonable to sup- 
pose that any slight kink in his hereditary 
nervous disposition might give way." In the 
family histories of those who become "Star 
Fliers" there is nothing for debate. 

Not only does a "kink" in the nervous make- 
up which comes down the family line consti- 
tute a flaw which may result in a break, but 
a former break-down may leave a weakness 
for years undetected. One never knows where 



28 THE AVIATOR 

a weak link lies until the breaking strain is 
brought to bear. A number of strange cases 
come to light in the psychiatrists' records. 1 
A rather typical example is as follows: A 
lad of nine set fire to his sister's hair with a 
Roman candle and burned his hand. He was 
extremely upset by the shock and suffered 
nightmares. It passed as an incident in child- 
hood. Twelve years later, as a balloon ob- 
server, he took to his parachute when the bal- 
loon was threatened. Again the haunting 
dreams, which finally took the form of burn- 
ing his home. He became a "debility" case. 
It was with difficulty and only after question- 
ing that he recalled the incident in boyhood. 
Nevertheless, no psychiatrist, who had expe- 
rience with this sort of trouble, will doubt the 
connection between the two experiences. It 
is necessary to know whether any of these 
childhood episodes, whose results are so often 
concealed, have occurred in the past life of the 
man who gives way to the strain; especially 

x Op. cit. p. 1 1 a. 




NERVE AND NERVES 29 

when the break-down seems out of proportion 
to the apparent cause. 

Often the flier has nothing in his heredity, 
or his early history, to indicate a weakness. 
The trouble comes from strain plus some emo- 
tional shock. The two are too much for him. 
The cause may be mental, the effect is insta- 
bility and heightened excitability of his nerves. 
The%e disorders affect centers controlling his 
heart, breathing, blood-pressure and even his 
reflexes. He cannot concentrate his attention, 
his memory is poor, he lacks interest and be- 
comes sleepless, restless and irritable. Such 
symptoms point to disturbances in his higher 
centers. 

To anyone who thinks only in terms of cour- 
age and cowardice, the man who refuses to 
fly after seeing a friend crash is simply a 
coward. 

If we were limited to a general knowledge 
of human nature, our opinion would be 
very low of the officers who "broke down" 
after they had learned to fly and were 



3 o THE AVIATOR 

about to start for France, or of the men who 
gave up flying after they had been up alone 
once or twice. 

After this survey of the machinery of the 
flier, surely there will be few who will think 
of aviators in terms of courage and cowardice 
only. It is, of course, true that a man is not 
a machine. If he were, a mental state could 
never cause a physical collapse. By the same 
reasoning, the mental state may do much to 
avoid the collapse. Just here the personality 
of the man comes into play. If he has formed 
the habit of dismissing the unpleasant from his 
mind, of bobbing up with a smile each time 
he gets a shock, he has gone a long way toward 
controlling his instinctive reactions. On the 
other hand if the ancient racial habits, the in- 
eradicable instincts and emotions, are dispro- 
portionately strong, no effort of his will can 
override them. He is not a coward; he is 
simply disqualified from flying, because of a 
physical disability! Navigating the air calls 



NERVE AND NERVES 31 

for a kind of nervous balance which all human 
animals do not happen to possess. 

Our forefathers partly recognized the physi- 
ology of courage. They located it in the 
heart. Indeed, the word "courage" is de- 
rived from the Latin word "cor" meaning 
"heart." In early French it is "corage" and 
it was taken over by the English as a word 
they needed in their business with the French. 
Still earlier Horace declared, in one of his 
odes, that the first man who ventured out to 
sea in a frail craft among "the rolling mon- 
sters of the deep" had a heart of oak, bound 
around with a triple band of brass. It is in- 
teresting to speculate on the language the poet 
would have used to describe the organs of an 
aviator. However, from Horace down, there 
has been a strong suspicion that the unfortu- 
nates who did not possess stout hearts were in 
some way to blame for their misfortune. If 
a man were "lion-hearted" it was to his credit, 
if he were "cow-hearted" it was to his shame. 



32 THE AVIATOR 

Perhaps there was some wisdom in this, after 
all. Experience does teach us that we are 
not altogether the masters or the victims of 
our constitutions. 




CHAPTER III 

CONTROLLING THE PLANE 

The first concern of every pilot is self- 
control. Once assured of that, his next con- 
cern is the control of the airplane. Along 
with self-control must go a number of other 
qualities. Quick decision and unchanging de- 
cisions are among the indispensable traits. 
No man can vacillate when a question of land- 
ing in one of two places is offered for a de- 
cision in two seconds. The picturesque halts 
of the cinema hero are denied to the aviator. 
He cannot hesitate, glance back, or even regis- 
ter an expression of uncertainty, when the ma- 
chine must be placed on one side or the other 
of a fence, which he approaches in a slow 
ship at the rate of a hundred and fifty feet in 
two seconds. It requires about 2/10 of a sec- 

33 



34 THE AVIATOR 

ond for an alert aviator to see a danger and 
move his hand, and it requires about 5/10 of 
a second for him to make a decision and the 
right reaction when one of three or four well- 
known dangers may appear. If he is speed- 
ing through the air in a fast machine at the 
rate of 150 miles an hour, and another machine 
is coming toward him at the same rate, 220 
feet are covered in that half a second of de- 
cision. If he is a little slower in deciding 
and requires about a second to reach his de- 
cision, a twelfth of a mile is used up in the 
time of his decision — or indecision. In mo- 
ments of sudden danger the quick decision 
means life. A sluggish type of nervous sys- 
tem may survive fair-weather flying, when 
aviation is on a peace footing, but it could 
not last long among unusual and sudden 
perils. 

Quick decision is a native trait. A nervous 
system is either capable or incapable of such 
actions. Perhaps the knack of making and 
keeping a decision is also a native trait. It 



CONTROLLING THE PLANE 35 

is conspicuously absent in some people. This 
is often a symptom of a fatigued, or disord- 
ered, nervous system. In part, the power of 
quick decision is a matter of habit and can be 
cultivated. For good flying it is a prime req- 
uisite. Of very little service is the ability to 
decide quickly, if the decision is reversed a 
moment later. The man who starts to pass you 
first on the right, then on the left, and splits 
the difference by running into you, has no 
business in the air. 

Naturally, the senses which inform the avia- 
tor of what is going on around him are the 
most valuable instruments he possesses. Eyes, 
ears and the senses of touch and balance must 
be in perfect condition. The materials they 
supply his mind must be quickly received and 
used. It is not enough for the eye to detect a 
slight difference in the shades of green in two 
neighboring fields. The mind must grasp the 
significance, for it makes some difference 
whether one lands on a lawn or a cornfield. 
A color-blind eye or an unreceptive mind are 



36 THE AVIATOR 

equally bad. Every moment the airplane is 
in motion, the ears are receiving information, 
and it is of a kind which cannot be ignored. 
The sense of pressure from the controls as the 
machine cuts its way through the air gives 
further information of what the craft is do- 
ing. Even the change of the wind against 
the cheek has a message for the alert mind. 
Every sense that can convey a meaning serves 
a purpose for the aviator and not one of these 
meanings can he afford to neglect. It is a set 
of perfect instruments he must have and they 
must all be used. Not all of his faculties 
are in action all of the time, of course. But 
he must be capable of using all of them at any 
time. The list of accidents bear witness to 
this. 

"It has been estimated in the British Serv- 
ice that of all fliers lost to active flying service 
less than 2 per cent are put out by German 
bullets, only 8 per cent, as the result of a de- 
fect in the plane, the remaining 90 per cent, 
because of the physical condition of the 



CONTROLLING THE PLANE 37 

pilot.' 7 * Undoubtedly some of these fatal- 
ities are due to conditions resulting from lack 
of adequate oxygen. Dr. Anderson kept an 
account of the accidents that occurred in an 
English flying school during six months. In 
this time some 9000 flights were made and 58 
airplanes were wrecked or crashed. When 
the causes of these accidents were analyzed 
he found one crash due to a defect in air- 
plane, four were unavoidable, four due to 
brain fatigue, seven to "loss of head" and 
forty-two due to "error of judgment." Of 
course, it is hard to say just what enters into 
an error of judgment. It may be a simple 
mistake, as when one forgets to make a wide 
turn in turning from against a strong wind 
to with the wind. More probably it is an 
error of a somewhat subtler character. For 
example one pilot, whom I know, found him- 
self using the wheel for the rudder when his 
machine reached the ground. He was never 

1 Air Service Medical, published by the War Department, 
Washington, D. C, p. 207. 



38 THE AVIATOR 

guilty of this trick when he was in the air. The 
explanation lies in the man's habits. Years of 
driving an automobile, turning the wheel to 
direct the machine with reference to the 
ground formed habits which were deeply im- 
planted. They were overcome when the 
ground was so far distant from the earth that 
it no longer suggested the moving ground 
about an automobile, but as soon as the old 
situation reappeared the old habits asserted 
themselves. An error of judgment in his case 
was a reassertion of deep-seated habits. It 
was not simply mistaking the wheel for the 
rudder. "Errors" then need explaining. To 
understand them we must review the art of 
flying a little. 

To keep the airplane off the ground three 
things are indispensable. One is motion 
through the air at a sufficient rate to sustain 
the weight of the machine ; a second is main- 
taining the position of the machine as the re- 
sisting surfaces are supported by the air; the 
third is, naturally, directing the machine in 



CONTROLLING THE PLANE 39 

its course. To accomplish these the pupil 
must learn to control the speed of his ship in 
the air, to control her position laterally and 
longitudinally and to steer her. The con- 
trol of the speed calls for some experience 
with gas engines, a knack of listening to their 
action and governing their speed by switching 
the gasoline off and on. It is not as difficult 
as supplying the automobile with gasoline, 
as the throttle is usually opened on the air- 
plane and left open until it is time to land. 
The chief difficulty in speed control is with the 
habit of estimating the speed in terms of how 
fast objects are moving past. This is all 
right for anything which moves upon the 
ground, but it is all wrong for anything mov- 
ing in the air. Only one thing is of impor- 
tance in the airplane and that is to move 
through the air. Slowly one acquires an air 
sense, so that he is conscious of his speed in re- 
lation to the air. The control of the position 
of the craft laterally is accomplished by mov- 
ing a lever, or a wheel, from right to left, 



4 o THE AVIATOR 

and back and forward to change the fore and 
aft position. In fast machines a very slight 
movement results in a very quick change of 
position. Gradually, one acquires a feeling 
of position-changes with the changes of the 
lever. It comes to him in the same way the 
feeling of controlling the bicycle comes, and 
he begins to keep his balance in two planes 
just as he learned on the bicycle to do it in the 
one plane. Steering the course calls for foot 
movements, which must be accompanied with 
movements of the wheel. A turn of the rud- 
der necessitates a new balance. One of the 
difficult things for the beginner is to match 
his hand work to his foot work in banking his 
ship around a turn. All of these movements 
are simple and easily made. The art con- 
sists in the finesse and coordination with 
which they are made. 

Flying, like any other performance, is an ac- 
quirement of new habits and combinations of 
habits. To take a simpler and more familiar 
accomplishment first; riding a bicycle affords 



CONTROLLING THE PLANE 



4* 



a good illustration. After you have learned 
it is not hard to discover what you are doing. 
Your habits are so well formed that you can 




5k 



TVftNING to left 





The Controls of the Airplane 

The upper figure illustrates the relation between the 
movements of the rudder-bar and the rudder. 

The middle figure gives the relative positions of the 
control lever and the elevators. 

The lower figure shows the aileron connections with 
the control lever. 



42 THE AVIATOR 

watch them while they work. To find what 
habits you have, try eliminating some of the 
things the habits are built upon. Loosen the 
saddle so that it does not move with the side 
motion of the machine. Right away the dif- 
ficulty of balance is enormously increased. 
Remove one pedal. Notice the difficulty of 
righting the machine when it tips to the side 
of the missing pedal. Try riding with the 
eyes directed to the sky. The trouble you ex- 
perience now is due to the absence of that in- 
direct vision that constantly told you your 
position relative to the ground. Take a 
strange machine with a different pitch to the 
steering head;. Your steering is bad until 
you get the "feel of the ship" as an aviator 
would say. The whole performance is a 
group of habits. They are built up without 
the clear knowledge of their formation. Few 
riders have analyzed what they do as they bal- 
ance themselves. Some do not even realize 
that the constant turning of the handle bars 
is correcting their balance by turning the ma- 



CONTROLLING THE PLANE 43 

chine into the direction it is leaning. Fewer 
still realize how they get their cues of lack 
of balance and how they use the cues. 

Such ignorance is very common when the 
new accomplishment is based on actions 
learned without seeing and understanding ex- 
actly what is being done while it is being done. 
If the arm stroke of swimmers is compared 
with the leg stroke, it is very evident that the 
arm work is much more alike among swim- 
mers. They see others and can see their own 
arm movements and correct them. The leg 
movements are controlled by the sense of touch 
in the water, the sense of motion and muscle 
strain. Often the beginner tries to see what 
is going on in the rear that is not doing just 
what he wishes. Could he see his legs and 
correct their behavior he would make great 
improvement. Try to think in terms of 
movements instead of in terms of things seen ! 
Notice the vagueness and uncertainty. It 
often helps the beginner trying to row in a 
shell to practice in a dummy shell before a 



44 THE AVIATOR 

mirror. Then he can see his movements and 
make the correct coordinations. After they 
are seen, analyzed and understood the habits 
can be started which later are directed by the 
sense of movements and muscle strain. 

In learning to fly one may unite the two 
methods of learning, namely, seeing and feel- 
ing. He should see and understand the ac- 
tion of the controls, but he must learn to direct 
them by the feeling of the ship's motion and 
position and by the resistance in the stick and 
rudder. 

The natural movements are easily formed 
into habits. It is very natural to pull the 
stick back to raise the forward end of the 
ship. 1 Everyone has made this movement 
to accomplish similar ends. So, too, it is nat- 
ural to push forward to bring the nose of the 
ship down. One naturally leans forward, or 
backward, prior to descending, or rising, in 
an airplane. Such a control comes quickly. 
The lateral control is another story. True, 
the motion is a natural one. To draw the left 

1 See Figure II, page 41. 



CONTROLLING THE PLANE 45 

wing up one would naturally pull to the right, 
or to lower it push to the left. This the rig- 
ging of the ailerons is designed to accomplish. 
All goes well after the pupil gets the habit. 
At first, when one sees an aileron go down, he 
is apt to think that wing will go down, though 
a moment's thought tells him the reverse. A 
few students are troubled with their ailerons 
while they are in the seeing and understand- 
ing stage. When the correcting of side mo- 
tions has become a matter of feeling, there is 
no confusion. 

The rudder bothers some pupils much more 
than it does others. The airplane moves in 
the direction you thrust your foot. If you 
would turn to the right, the right foot is thrust 
forward. Now this movement is the reverse 
of such steering as one does on a bicycle, or 
a sled, or an automobile. In these vehicles 
the bar or wheel turns in the direction you 
wish to go, not away from it. I found that 
the knack of steering the airplane came eas- 
ily when I thought of the action of the rudder 



46 THE AVIATOR 

in striking the air when the right or left cable 
was drawn. tBy keeping a visual image in 
mind of the position of the rudder, I could 
overcome the tendency to turn the rud- 
der bar in the direction I wished to go. 

In acquiring habits of making a certain class 
of movements it is wise to go slowly and think 
out the situation, if you can, as you go. For 
example, in driving an automobile on a slip- 
pery road when the car begins to skid toward 
the side of the road, all one's past habits 
of steering lead him to try to steer it back 
to the middle of the road. If he has thought 
out the situation he will turn his steering 
wheel in the opposite direction and start his 
front wheels rolling in the direction the car is 
skidding. After a few skids the habit is eas- 
ily formed. The skidding motion of the car 
gives a certain feeling which is promptly met 
by the correct turn of the wheel. At first 
there must be an intelligent understanding of 
the skidding motions, later the habit may be 
trusted. 



CONTROLLING THE PLANE 47 

I dwell on this feature of learning to fly as 
a number of cadets in the flying schools, and 
indeed, a number of aviators with whom I 
have talked, are unable to explain just how 
they fly. Not a few take refuge in the state- 
ment, "You just do it instinctively," which 
means they have acquired their flying habits 
without analyzing them. Now, that is all 
right when things go well, but in an emergency 
habits need correcting. 

From this comparison of flying, by seeing 
and understanding as contrasted with flying 
by feeling and habit, we can distinguish be- 
tween two types of fliers. One becomes a 
mechanical flier, the other develops into a nat- 
ural flier. The former is sometimes known 
as a "radiator flier," owing to his constant 
watch to keep the upper part of the radiator 
above the horizon. He never acquires the 
sense of the ship's position sufficiently to en- 
able him to tell whether she is nosing up or 
down, so his eye is ever on the horizon. Of 
course, this means that his attention is largely 



48 THE AVIATOR 

absorbed in keeping his levels, and that 
means that he has less thought to give 
to other things, — map reading, formation 
flying, photographing and what not. He 
is in as awkward a position as the cyclist 
who has to keep his attention on the balancing 
of the wheel all the while. A natural flier 
soon learns whether his plane is on a level. 
He substitutes the feeling of his position for 
the horizon and controls his ship by that. He 
feels the air on his cheeks, hears it in the wires 
without giving a conscious thought to it, and 
corrects his controls accordingly. This means 
that the signals to which he used to attend 
with the greatest attention are now relegated 
to the "fringe of attention" as the psycholo- 
gists say. By this means the center of his at- 
tention is free to turn to many other things. 
There is nothing mysterious about this. 
Everyone has been doing just this sort of thing 
all his life. At first the holding of a pen in 
the hand took so much attention we could not 
think of what to write, the spelling of the 



CONTROLLING THE PLANE 49 

words in the beginning obscured what we 
read, controlling the bow and holding the 
violin made the score impossible to read, the 
place and the action of the automobile's ped- 
als, wheel and levers made it impossible to 
talk and be chauffeur at the same time. 
Gradually the matters that required such at- 
tention were shifted to the "fringe." 

In terms of the nervous system something 
like this goes on as we master new accomplish- 
ments. The cortex of the brain, where con- 
sciousness is dominantly resident, is a vast 
maze of myriads of nerve connections. A 
number of these nerve tracts transmit the first 
impressions of the thing we are handling and 
seeing from one part of the brain to another. 
In doing so we are keenly conscious, that is 
we are "all attention," As these processes 
become frequent and the parts engaged are 
frequently in connection, the resistance in the 
nerve tracts is lessened, the currents pass more 
easily. With this advance in making con- 
nections readily the consciousness accompany- 



50 THE AVIATOR 

ing the process diminishes. That is to say, 
consciousness is a function of the resistance to 
nerve current The greater the resistance the 
clearer the attention, for attention is simply 
the clearest sort of consciousness. In the case 
of an instinctive action the nerve connections 
are so complete little consciousness attends 
them. In cases where habits (or good nerve 
connections) cannot be formed we can never 
cease attending. This is the case in many 
of the complicated duties in life. 

As brains are by no means alike, we should 
naturally expect differences in the conscious- 
ness of different people. One of the most 
interesting of these differences is in the amount 
of consciousness present at any one moment. 
As we would expect, some brains have the ca- 
pacity for more connections, amid the great 
meshwork bf nerve connections, than others. 
This results in a more expansive type of at- 
tention, or what is called a "broad span of 
attention." Usually, it is measured by de- 
termining how many things one is capable of 



CONTROLLING THE PLANE 51 

attending in a second or a fraction of a sec- 
ond. Measurements of this sort prove there 
are broad- and narrow-spanned types. In 
everyday life we easily detect the* more con- 
spicuous examples of this. Rapid readers 
are broad-spanned. Their eyes make few 
pauses as they read. They grasp more in 
these pauses than the narrow-spanned. Every 
good organist, who reads the scores for his 
keys and pedals must be broad-spanned — the 
violinist may be the opposite type, as his 
work does not demand attention upon so many 
things. Of course a narrow-spanned orches- 
tra leader would be an impossibility. 

It is not difficult to imagine the advantages 
the broad-spanned type has over the opposite 
type in flying an airplane. The former has 
many advantages over the latter if all other 
capacities are equal. Indeed, in learning to 
fly, one of the most frequent complaints is 
directed against the number of things you 
have to attend at the same time. As one poor 
fellow remarked, it is worse than Christmas 



52 THE AVIATOR 

shopping, when you have bundles in both 
hands, under both arms and an umbrella to 
hold over a lady. Apart from simply doing 
numerous things the aviator must do them all 
together. It is not unlike juggling a number 
of balls. It is disastrous to the ensemble to 
ignore one, though it be just one little one. 
This explains why it is that a narrow-spanned 
aviator finds his ship nosing up, or down, 
while he leans over the side to take a photo- 
graph, and why it is that he flies badly in 
formation when his attention is absorbed in 
the leader's manoeuvers. Later we shall see 
how the loss of oxygen affects his attention. 

Perhaps it should be stated that the princi- 
ples of "span" apply not only to the clearest 
part of attention, but also to what we have 
called the "fringe." There is some reason 
to believe that the broad-spanned type is also 
the wide-fringed type. This type not only 
consciously attends many things at one time, 
but also carries a number of things in that 
sort of penumbra of consciousness we call the 



CONTROLLING THE PLANE 53 

"f ringe." To revert to the organist by way of 
illustration, 'his attention is on the scores, 
the keys and pedals, in the "fringe" he is 
aware of the choir leader marking time, of 
the time to turn the page, awhile further re- 
moved from the tenter of attention, indeed 
so far removed from the clearest part of con- 
sciousness that they are practically uncon- 
scious (until disturbed) are the habitual move- 
ments of fingers and feet, of head and body 
positions. 

Fortunately the aviator has no such elabo- 
rate task. However, an enumeration of his 
duties totals rather high. First he must steer 
his course. This means attention to the 
ground, or the compass, primarily. With the 
steering goes attention to altitude, is it increas- 
ing or diminishing? The engine is all im- 
portant. He must always hear it. The wind, 
if present, and choppy, will keep him alert. 
The balance of the plane calls for a "fringe" 
that is concerned with the "feel of the ship," 
and a constant response on stick and rudder. 



£ 4 THE AVIATOR 

Then that gasoline gauge cannot be forgotten. 
The whistle of the wind in the rigging is al- 
ways saying something. If he is flying in 
formation, or observing the terrain, or wire- 
lessing a message, these duties claim his at- 
tention primarily and all else must be in the 
"fringe," or relegated to the slight conscious- 
ness of habitual actions. 

It would appear then that the success of the 
aviator depends in a large measure upon the 
way in which he succeeds in acquiring certain 
habits. The easier it is for him to make his 
performance automatic, the more freedom he 
has for thinking and planning. To habitual- 
ize his work is not as simple as one might 
imagine. There are pitfalls in the way. A 
bad habit will begin as readily as a good one, 
and very subtly. 

It is a poor plan to attempt to acquire a 
new habit when you are fatigued. It is worse 
to persist when you have begun making mis- 
takes and have to work constantly to over- 
come them. Seize the hour when you are 



CONTROLLING THE PLANE 55 

fresh and things come easily. Often the hesi- 
tancy acquired by uncertainty, or nervousness, 
will persist as a nagging habit to be overcome. 
For example, in making a right turn the 
torque of the propellor makes it more difficult 
than a left turn. Some instructors grew im- 
patient and roundly cursed the clumsy pupils 
who bungled their right turns. As a con- 
sequence a hesitancy showed itself with these 
pupils, which they had hard fights to over- 
come, whenever a right turn was needed. 
Saner teaching would have demonstrated the 
reasons for the difficulty, and given constant 
practice till the habit built up. 

Some of the needless accidents in our flying 
schools were due to men attempting to carry 
on their habit work when they were stale, or 
half sick, or recuperating from a "night be- 
fore." A half-formed habit is a bad thing to 
trust. When one relegates an action to the 
"fringe" and the mind is not alert there is a 
splendid chance for a crash. Good condi- 
tion is a sine qua non in flying. But good 



5 6 THE AVIATOR 

condition is not always as obvious as it might 
be. Occasionally, one feels quite fit, but is not 
fit, nevertheless. Often a man goes stale. 
His nerve energy has small resources. But 
on a crisp fall day he feels "snappy" and 
wishes to fly. The strain of flying soon saps 
his reserve and he is in no condition to keep 
the fine balance and coordination in move- 
ments and the alert perceptions needed to 
make a good landing. 

The flight surgeon was a life saver, in more 
ways than one, to many a cadet in the flying 
schools. His knowledge of human nature 
and of science was of great value. Who but 
he could advise with confidence and success 
a cadet, who was in splendid health but dis- 
tracted by worry, to keep out of the planes? 
An average instructor would contend that 
such a cadet should fly, "To keep his mind off 
his troubles." "Not so," said one flight sur- 
geon, "When his mind reverts to the sick 
mother and the trouble at home, there will 
be moments when attention relaxes, when the 



CONTROLLING THE PLANE 57 

newly formed habits cannot be trusted. The 
risk is too great." That cadet stayed 
"grounded," until he won control of himself. 

In controlling the plane there is a balance 
of abilities, some acting in full consciousness, 
some in a partly conscious way and some in a 
very faint, perhaps sub-conscious way. These, 
all, are subject to the physical condi- 
tion of the man. Nerve energy varies as 
truly as does other forms of energy. A tired 
flier may find all going well in the clearest 
area of consciousness, but he cannot cheat 
nature. In the outskirts his sentries are 
drowsing, perhaps he does not notice the rev- 
olutions counter, or the gasoline gauge, or 
that occasional miss in the engine. His cour- 
age is splendid, but his control is subtly de- 
ceiving him. 

To sum up; the control of the airplane is a 
matter of habits. No one can step from the 
ground into an airplane and run it on the 
basis of the knowledge he possesses. Only by 
forming one habit after another does the art 



58 THE AVIATOR 

of controlling the aircraft build up. It is 
the mechanical response of the nervous sys- 
tem to the stimulations it receives which makes 
flying possible. What the nerves of the bird 
acquire by racial habit the human flier must 
gain by practice. Such mechanical actions 
are, of course, directed by his conscious wishes, 
but fundamentally the human flying-machine 
is dependent upon the structure and function 
of his nerve machinery* 

How the various parts of this elaborate sys- 
tem function in flying is the study for separate 
chapters. One of the most important is the 
mechanism which enables all types of fliers to 
keep their equilibrium in the air, and which 
yields the sensations of motion and balance. 



CHAPTER IV 

THE SENSE OF MOTION AND 
OF BALANCE 

Certainly there can be no sense about 
which we know so much and so little as the 
sense of motion. We knew we liked it when 
we were in the cradle and we took pains to 
make the hand that rules the world act ac- 
cordingly, We knew we liked it when we 
swung in swings, slid on sleds, and rode the 
merry-go-round. We experimented with it. 
We whirled on one heel until we were 
drunken dizzy and watched the landscape go 
dancing by when we stopped. The more 
observant among us noticed that we always 
saw the landscape dance past in the opposite 
direction to the one in which we had been 
spinning. When we bent over with the face 
to the ground and spun around, we found that 

59 



60 THE AVIATOR 

we had to fall down as soon as we stopped 
turning and straightened up. Strangely 
enough, we always fell in the same direction 
as the one in which we had been turning. 
Probably our early experiments had been long 
forgotten when we took the tests as candidates 
for aviation, but some recollection of them 
must have returned when we were spun in the 
"turning chair." Again objects danced past 
in the opposite direction to our turning while 
the officer in charge watched the nystagmus 
of the eyes, again we fell over to one side when 
we attempted to sit straight after the prer 
scribed "ten turns in twenty seconds" with the 
face toward the floor. Undoubtedly, we were 
somewhat surprised to learn that the dizziness, 
against which we fought so hard, was per- 
fectly natural and that if we were to become 
aviators we must have a certain amount of it 
or we would not be normal types. 

Dizziness, therefore is an asset and not a 
liability for the aviator! That is rather hard 



MOTION AND BALANCE 



61 



SIDESLIP INDICATOR, 
bubble. 




FO&L AND AFT LEVEL 
Sectional Side View 




Dashboard 



Instruments for Detecting the Lateral and 
Longitudinal Movements of the Airplane. 



62 THE AVIATOR 

to believe. Of course, it is only part true, 
but the part of it which is true is important. 
Nature's instruments for informing us 
whether we are moving and whether we are 
keeping our balance are very delicate, and one 
of their by-products is dizziness. If they 
are not functioning, there will be no dizziness. 
It is interesting to compare Nature's device 
for informing the bird, fish or man whether 
he is turning with the device used in the air- 
plane for the same purpose. It is necessary 
to know whether the airplane is turning up- 
ward or downward, "nosing up or down," and 
to accomplish this a fore-and-aft level has 
been devised. As the cut shows, the level is 
merely a triangular glass tube half-filled with 
a liquid which sinks in the vertical tube as the 
machine turns upward and rises as it turns 
downward, It ,is, also, necessary to know 
whether the machine is turning in such a way 
that one wing is becoming lower than the 
other. A sideslip indicator accomplishes 
this, just as a spirit level would do. When 



MOTION AND BALANCE 63 

the machine turns from its course, the com- 
pass tells the story. So there are three direc- 




Organs of Motion and Balance 

The three semi-circular canals which detect turning 
movements in three planes: (i) the external, or hori- 
zontal, canal; (2) the superior vertical canal; (3) the 
posterior vertical canal. 

The two sacs for detecting changes in positions of the 
head, and motions: (4) the utricle; (5) the saccule. 

(6) The nerve leading to the brain. 

tions or planes in which the airplane may 
turn; up and down in a vertical plane; from 



64 THE AVIATOR 

side to side in another vertical plane, at right 
angles to the former; and around to the right 
or left, in a horizontal plane. Nature solves 
the problem of turning in these three planes 
by having an instrument something like the 
fore-and-aft level lying in each of the three 
planes. These three levels are known as the 
three semi-circular canals, and they are lo- 
cated in the inner ear just back of the cochlea, 
which is devoted to hearing. As their name 
implies, they are hollow half circles, joined 
together, as is shown in the cut on page 63. 
A liquid fills all three of them. When they 
move in any direction, the liquid moves in 
the opposite direction. The canals are com- 
pletely filled with liquid and, unlike the level, 
the sides of the canals have a number of hair- 
like bodies projecting into the liquid. These 
minute hairs are the endings of the vestibular 
branch <of the auditory nerve. When the 
head is turned in any one direction, the liquid 
in the canals begins to move, this moves the 
hair-like projections and a stimulus is sent out 



MOTION AND BALANCE 65 

along the nerves to the brain. Each particu- 
lar bending of these lines of little hairs is in- 
terpreted by consciousness as a movement, as 
a turning in a certain direction. Anything 
which would make the liquid move the hair 
cells would result in a sensation of turning. 
That is why warm water flowing into the ear 
and causing a change in the specific gravity 
of the liquid in the canals causes it to move, 
and one gets a sensation of moving though the 
head is still. On the other hand, if we are 
turned very slowly, with the eyes closed, we 
have no sensation of turning, for the liquid 
moves together with the canals and hair cells 
and so does not bend th,e latter. Only when 
the canals and the liquid do not rroove together 
are the hair cells bent. That happens when a 
sudden movement is made. When both the 
canals and their liquid have been turning at 
the same rate, and the head is suddenly 
stopped, allowing the liquid to continue its 
motion, the hair cells are then bent and we 
have the sensation of moving though we are 






66 THE AVIATOR 

still. This sensation continues until the hair 
cells are again in their normal position. This, 
of course, is what happens when the turning 
chair stops after some ten or twelve turns in 
the same direction. 

About a hundred years ago a French physi- 
ologist by the name of Flourens experimented 
upon some pigeons. He cut the semi-circular 
canals one by one and observed the effects. 
It seemed clear that his animals were affected 
in their movements according to the canals 
cut. A horizontal canal on one side, when 
cut, caused movements in that plane ; these in- 
creased when the corresponding canal on the 
other side was severed. With both horizon- 
tal canals injured, the bird would not fly un- 
less tossed into the air and then it could not 
guide its flight. With all the vertical canals 
severed, the creature made strangely forced 
movements. When all the canals are injured, 
a pigeon cannot coordinate its movements at 
all, indeed it cannot stand unaided. I have 
watched a pigeon which had thoroughly re- 



MOTION AND BALANCE 67 




The Simplest Organ for Giving the Sensations 
of Motion and Balance 

(1) Round, mineral particle, supported by (2) hair- 
cells that attach to (3) the nerve, which penetrates (4) 
the membrane of the sac. Each movement of the animal 
moves the particle among the hair-cells and gives rise to 
sensations indicating changes of position. 

covered from the effect of the transection of 
the canals. It was with difficulty it could be 
made to use its wings. When thrown into the 



68 THE AVIATOR 

air it flew directly upward until it struck the 
ceiling of the laboratory. Then it fluttered 
awkwardly down to the floor. 

In birds and fish the three semi-circular 
canals are well developed. In one primitive 
form of fish there are but two canals. In man, 
the three canals are not developed any more 
highly than in the lower animals ; though the 
other part of the ear, which has to do with 
hearing, is more elaborately developed. In 
the mollusk we find another device of Nature 
which the aviator has not yet imitated. It is 
a sort of substitute for the semi-circulars. It 
is a small cyst, or sac, into which many hair 
cells project from all sides, holding a solid, 
round body in the center of the sac. Any 
movement in any direction will cause the solid 
ball to press hard against the hair cells which 
must support it. Such a pressure results in 
a sensation of movement. Any shift of the 
position of the ball would be interpreted as 
a shift in the position of the body. Many 
fish have such cysts but instead of one solid 






MOTION AND BALANCE 69 

body they have a number of little hard parti- 
cles which lie among the hair cells. These are 
known as otoliths. If these otoliths are re- 
moved and minute iron filings put in their 
place the fish can be moved in any direction 
by bringing a magnet near his head and draw- 
ing the filings against the hair cells. 

In man this sac is represented by two little 
sacs which are connected with the semi-circu- 
lar canals ; the lutricle and saccule. Minute 
otoliths lie among the hair cells of these sacs 
and any movement which disturbs their posi- 
tion gives rise to sensation. True, the sen- 
sation is very vague and is not located in the 
ear, and may not be detected as a sensation. 
Nevertheless, it must play a part in giving us 
our sense of position and motion. 

One very vivid experience we can connect 
with the machinery of the inner ear is trial de 
mer! First, the unusual agitation in the 
liquid of the canals and sacs, due to the ship's 
motion, sends impulses to the cerebellum, or 
small brain, and one gets the sensation of ver- 



70 THE AVIATOR 

tigo. Then the evil spreads in ways all too 
familiar to need description ! Animals which 
grow seasick from unusual motions lose that 
trait when the ear nerves are severed. Deaf 
mutes whose inner ears are injured suffer no 
pangs at sea. Fortunately Nature gives some 
alleviation. After a season of suffering we 
grow accustomed to the pitching and tossing 
of the sea ; or rather of the liquids of the sacs 
and canals. There is a tolerance developed, 
or a compensation established. The machin- 
ery continues to work, but the ill effects grow 
less. 

The connection of the inner ear with other 
parts of the nervous system is very interesting. 
Recent researches show that the cerebellum, 
lying at the back and base of the skull, receives 
a branch of nerves which pass out from the in- 
ner ear, and the cerebellum acts as a sort of 
controller of all movements. It is easy to see 
why the inner ear is closely connected with it. 
In such acts as dancing, boxing, or driving 
an automobile, the direct command to each 



MOTION AND BALANCE 71 

muscle comes from a center in the large brain, 
but the combination and general direction of 
these new impulses is evidently mediated by 
the small brain. Some progress has been 
made in locating injuries in the latter by not- 
ing disturbances in movements of the arms, 
legs or trunk. Not much can be said about 
the sort of consciousness which is resident in 
the cerebellum, but it would seem to be a sort 
of piece de resistance to all consciousness, 
acting as a background for all of our thoughts, 
and orienting us amid our surroundings. 

Another branch of the nerve running from 
the inner ear goes to a center which controls 
the movements of the eyes. Stimulations 
coming into this center from the organs of the 
inner ear result in reflex movements of the 
eyes. If you are seated in a revolving chair 
and turned to the right quickly, and then sud- 
denly stopped, the eyes show a decided twitch- 
ing movement; which anyone close to you can 
see. The objects around you seem to go 
swimming by from right to left. The 



72 THE AVIATOR 

twitches are in the horizontal plane as the 
horizontal canals were the ones most affected. 
By close inspection it is apparent that the 
quick right and left movements of the eyes 
are not equally fast. In this case the eyes 
move quickly to the left and less quickly back 
again. It is an instance of nystagmus to the 
left. The reflex movement of the eyes is in 
the same direction that the liquid in the canals 
is flowing. That accounts for the slow 
movement in nystagmus. The quick return 
movement appears to be controlled from the 
cerebrum, a higher brain level; and we 
may think of it as an unconscious effort to 
bring the eyes back to their normal posi- 
tion. 

If the chair is turned from left to right 
ten times in twenty seconds and the occupant 
is stopped and told to reach out his hand and 
point to your finger, he will point past it to 
the right. He feels that he is now turning to 
the left and away from the finger and there- 
fore past-points to the right. If he were told 



MOTION AND BALANCE 73 

to rise and walk, he would have equal dif- 
ficulty in directing his movements. 




In this Position the Vertical Canals are 
Affected by the Rotation of the Chair 

If the turning is to the left the candidate will fall to 
the left when he attempts to sit erect. 

When the head is inclined forward to an 
angle of 120 degrees the vertical semi-circular 



74 THE AVIATOR 

canals which control side to side motions of 
the head now come into the horizontal plane, 
parallel to the floor. It is the position the 
aviator's head is in when he does a tail spin. 
Then, if one is turned quickly in this position 
from the right to the left and stopped when he 
seeks to sit erect, he promptly falls to the left 
side, perhaps it is truer to say that he throws 
himself to the left side. 

Should the head be inclined to the right 

shoulder in such a way that the third set of 
semi-circular canals are affected, we get the 
same effect that the aviator has when he does 
a "loop." As he seeks to bring his head back 
to a normal position after turning quickly 
from right to left, he will feel that he is fall- 
ing backward and will consequently throw 
himself forward. While his head is inclined 
he has the sensation of turning in a plane par- 
allel to the floor, but so soon as he sits erect 
the sensation is one of turning in a plane 
vertical to -the floor; that is, of falling vio- 
lently backwards. 



MOTION AND BALANCE 75 

The short and easy way of remembering 
how one will throw himself or past-point is 
to think of the direction in which the liquid 
in the canals will be flowing when the rotation 
of the head stops. He will fall and point 
in that direction, though he feels he is mov- 
ing in the opposite direction. By keeping in 
mind the positions of the three canals, it is 
not difficult to guess what results will follow 
from turning in any given direction. 

In "stunt flying" the ear probably plays an 
indispensable part. 1 A number of aviators 
who were whirled in the turning chair stated 
that they could get the same sensation there as 
when coming out of a "spinning nose dive" 
or a "loop," etc. Apparently the direction 
of flow of the endolymph in the canals is much 
the same in the chair as the airplane, for the 
types of movements are similar. That being 
the case, recall what happens when you lean 
forward with your face parallel to the ground 
and spin around in the chair. When you 

1 Air Service Medical, pp. 258 ff. 



76 THE AVIATOR 

come back to a vertical position, you promptly 
fall sidewise. Now picture an airplane do- 
ing a tight spiral or a tail spin. The avia- 
tor's face is again parallel to the ground and 
he is swinging in circles, not so small as in 
the chair but small enough to start the liquids 
in the canals flowing. When he seeks to 
straighten up, what happens? Will he be suf- 
fering with vertigo and afflicted with a nys- 
tagmus, which will cause him to throw him- 
self violently to the side of his ship? If so, 
he will fail to straighten out and will throw 
his ship into another spin, or he will "crash." 
Indeed, anyone who has spun in a chair, with 
the face to the floor, and then tried to sit 
erect cannot imagine how the aviator retains 
his control if he suffers the same experience. 
I threw myself against the side of the chair 
so violently, when I was spun, that I should 
have fallen to the floor had not someone caught 
me. The thing is irresistible! Obviously, 
the aviator does not get the same vertigo, or 
he has learned to tolerate it. The latter seems 



MOTION AND BALANCE 77 

to be the solution, for immediately after my 
experience in the turning chair an aviator 
who had been flying for a long time, one of 





\ 




A Series of Steep Banks in a Long Spiral Will 
Affect the Vertical Canals, and the Aviator Will 
Have a Strong Tendency to Throw Himself Back- 
wards and Sideways When He Levels off, Unless 
He has Become Accustomed to the Experience from 
Long Practice 

the best in the field, succeeded in rising to an 
erect position after the "head down" spinning, 
and experienced no difficulty at all. This 



78 THE AVIATOR 

would fit in with our knowledge of seasick- 
ness. Time and experience give an immunity. 

There seems to be a question whether the 
nystagmus subsides with constant repetition 
of the experiences of turning in the chair, or 
the plane. Sme experimenters claim it 
does, others declare it does not. It seems 
probable that it does if the repetitions are 
frequent and at 'close intervals. 1 This is an 
important question and should be definitely 
settled. Certainly the vertigo subsides after 
many experiences in the chair or plane. If 
the nystagmus does also, then we can insure 
the aviator against danger from dizziness by 
giving him training in the sort of evolutions 
he must make in the air while he is training 
on the ground. 

How valuable the organs of the inner ear 
can be for the aviator is a debatable question. 
It will be remembered that many a man has 
come out of a cloud flying upside down. 
When he had nothing in sight to compare 

1 Air Service Medical, p. 316, ff. 



MOTION AND BALANCE 79 

his position with, he did not know how he was 
flying. Some of the English experimenters 
felt that the sense of motion and balance 
gained from the canals and sacs was of little 
worth. They believed that the sight of other 
objects was the necessary cue. They thought 
that a man could tell a great deal about his 
movements by the changes in the position of 
his seat and controls, by the changes in wind 
on his cheeks, the sound of the motor and 
the whistle of the wind in the wires. Un- 
doubtedly there are many other cues, apart 
from those supplied by the inner ear, which 
are used by all good fliers. Probably he does 
not realize how many signs he actually uses. 
However "all signs fail in bad weather" and 
it would seem that night flying and cloud fly- 
ing are the aviator's bad weather. Then he 
needs other instruments than Nature's to help 
him. 

When we went into the war there was a 
considerable division of opinion concerning 
the part played by the organs of the inner ear 



8o THE AVIATOR 

in ordinary flying. An interesting experi- 
ment was made at Hazlehurst Field. 1 Sev- 
eral groups of people were chosen to go 
through the experiments. One group was 
normal in every way, a second group was com- 
posed of deaf mutes. Tests on the turning 
chair showed that this group had practically 
no nystagmus, no past-pointing and virtually 
no "falling." A third group was composed 
of tabetics, chosen because their type of 
paralysis precluded sensations of pressure giv- 
ing the cues. The inner ear was normal in 
this group. 

The experiments consisted in riding the 
subjects in the elevator of a forty-story build- 
ing. The elevator shafts were darkened and 
precautions were taken against air currents 
and sudden motions. The subjects indicated 
when a motion began and ended, and its di- 
rection. The results showed that the deaf 
mute group was unable to sense accurately 
the character of a slow motion to which they 

x Air Service Medical, pp. 242-258. 



MOTION AND BALANCE 81 

were subjected, though they were sensible of 
being subjected to some kind of motion. They 
could not get the illusion of reversal of mo- 
tion when the car stopped. The tabetics were 
peculiarly subjected to this illusion; they, like 
the normals, had no difficulty in detecting the 
up and down movements of the car. 

To learn how great a disadvantage a defec- 
tive inner ear may be to the aviator, another 
series of experiments were made, comparing 
the sensibilities of the deaf mutes and normals. 
This time the airplane was used. A number 
of officers went up as passengers with their 
eyes blindfolded. The pilot put the airplane 
at different climbing and gliding angles and 
at different banking angles. He also made 
"zooms" and "dips." His passengers were re- 
quired to indicate what the plane was doing. 
The results furnish an interesting comparison 
with those for the deaf mutes, who underwent 
the same tests. Among the deaf mutes their 
guesses as to the kind of motion to which they 
had been subjected were of the wildest char- 



82 THE AVIATOR 

acter. They had nothing to inform them ex- 
cept their deep sensibility and tactile sense. 
Nose dives and the "zoom," or upward move- 
ments, were carried out at such acute angles 
that it was remarkable that they guessed as 
inaccurately as they did. On close question- 
ing many of them admitted that they were en- 
tirely "in the dark" and felt that they must 
tear the bandages from their eyes. 

After making allowances for the nervous- 
ness of men flying in airplanes for the first 
time, and after allowing for a superiority of 
general ability in the officers who entered the 
tests, it does seem that the very poor show- 
ing of the deaf mutes must be due to their 
aural defects in very large part. 

This belief is further substantiated by some 
tests upon a number of aviators in which a 
tilting chair was used. The aviator while 
blindfolded was required to indicate when 
and in what direction the chair tilted as it was 
carefully and uniformly moved by mechan- 



MOTION AND BALANCE 83 

ical means. 1 It appears that the best esti- 
mates were made by the better aviators. 

An ingenious device was built at the Prince- 
ton psychological laboratory to measure the 
quickness and accuracy with which a combat 
pilot could swing his machine to a point where 
the machine gun would bear upon a target. 
It was known as the Eno-Fry Orientator. 
It gave a definite measure of a candidate's 
ability to whirl himself in any plane and to 
stop suddenly at a given mark. 

Another type of Orientator was the Ruggles 
Orientator. It enabled the student to prac- 
tice the movements of hand and foot which 
control the motion and position of an airplane. 
It also gave him some valuable experience in 
turning himself in every possible direction 
and in assuming every imaginable position. 
Such experience is valuable in at least two 
ways. First it accustoms the candidate to 
unusual positions. This is valuable. One of 

1 Journal of Applied Psychology, 1919; Vol. III. pp. 103-109. 



84 



THE AVIATOR 




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MOTION AND BALANCE 85 

the first men to do the "loop" successfully 
practiced for the trick in a chair that inverted 
itself! It was undignified but beneficial. 
Then, too, it enables the nervous system to 
habituate itself to turning movements. It is 
better to acquire a "tolerance" for vertigo and 
nystagmus in a machine fastened to the ground 
than in a machine spinning in the sky. 



CHAPTER Wi 

VISION IN THE AIR 

No one who takes a flight in an airplane 
ever escapes the question, "Weren't you 
dizzy?" Perhaps one's friends will be too 
considerate to question his feelings of nervous- 
ness, but they will never omit that question of 
dizziness. It would be a convenience if he 
were dizzy, then he would not be called upon 
to explain why he was not. As it is, most of 
us are not at all dizzy, during a flight; though 
we may often find ourselves a little dizzy 
when looking down from a high building; and 
it is certainly awkward to explain this in- 
consistency. Usually, the answer runs some- 
thing like this: "I don't know just why it 
is, but you don't get dizzy. You see the land- 
scape slipping away from you and you don't 
feel that you are rising into the air." Now, 

86 



VISION IN THE AIR 87 

this reply is not very satisfactory to either 
party. Let us see if we are not in a position, 
from what we learned in the preceding chap- 
ters, to give a somewhat better explanation. 

Anything which causes unusual eye move- 
ments and a blurring of vision may cause diz- 
ziness. People vary a great deal in this par- 
ticular. Some become dizzy from walking 
over a smooth, icy surface, some from simply 
closing one eye and attempting to move about 
as usual. Many of us become dizzy when we 
put on glasses which are not adjusted to our 
vision, or when looking through prisms. We 
complain that the "head swims 75 and we feel 
we cannot control our balance (well while 
"things look so queer." 

Clearness of vision depends, among other 
things, upon the six little muscles which con- 
trol the movements of each eye. They are 
arranged in the most natural way; one above 
and one below the eyeball, to give the up and 
down movements; one on either side to give 
the lateral movements and one above and one 



88 



THE AVIATOR 



below, fastened obliquely, to control rotating 
motions. The positions of the muscles may 
be seen very easily in the cut on page 88. 
When we look at any object these muscles 




Muscles Controlling Eye Movements 

A and B move the eye in the vertical plane ; C and D, 
in the horizontal plane; E and F control rotary motions. 

must keep the eye in a fixed position, or the 
object will blur. It is the same principle, 
of course, as in photography. If the camera 
moves the picture is spoiled. Rigid support 
may hold the camera in place; but, as the 



VISION IN THE AIR 89 

head is constantly moving the eyes must make 
compensating movements to keep their fixa- 
tion on any object This demands a very 
fine precision in the contraction and relaxa- 
tion of these muscles. Each one of them 
must have just the right tension. Moreover, 
as there are two eyes there must be perfect 
team work among all twelve of them ! Should 
one eye fail to coordinate with the other, ob- 
jects in vision would appear doubled. 

What happens to these muscles of the eye 
when the emotion of fear is aroused? Pre- 
cisely what happens to other muscles; there 
is an excess of adrenalin in the system and 
the irritability of the muscles is greatly in- 
creased. Just as the hand shakes and the 
knees beat a tattoo, so do the eyes lose their 
steadiness. Their slight tremors may not be 
apparent to another person, but the one who 
is frightened is well aware that the world 
around him does not look right. 

It is not necessary to be badly frightened 
to have a slight trembling of the hand, or 



90 THE AVIATOR 

shaking of the knees, or incoordination of the 
eyes. Embarrassment may give all of these 
discomforts. Any nervous anxiety may make 
a page hard to see, the print seeming to blur 
or double. So it is easy to understand how 
the vision may blur from the nervousness 
which afflicts many people as they look down 
from a great height. Here, then, is the secret 
of dizziness at heights ; the unaccustomed view 
may make some blurring of vision and cause 
some dizziness, but more probably the nerv- 
ousness incident to looking down causes the in- 
coordination of the eyes and this produces the 
dizziness. One is not usually nervous because 
he is dizzy; he is dizzy because he is nervous. 
Why, then, is not the airplane passenger 
dizzy on his first flight? Certainly, he is 
nervous enough. But there are some other 
traits the eyes possess, which work against diz- 
ziness. As soon as one fixes his gaze on an 
object and succeeds in holding it there the 
dizziness goes. Thus the nystagmus stops 
when one can fasten upon an object and hold 



VISION IN THE AIR 91 

the eyes fixed. This is not possible unless 
the nystagmus is rather weak. A more fa- 
miliar experience is the dizziness due to look- 
ing at running water, or a moving wheel, here 
the eye movements cause the dizziness and it 
stops as soon as the eyes rest fixed on any ob- 
ject. In the airplane it is easy to fixate the eyes 
on any large object below. There is a fasci- 
nation in watching it recede. The interest in 
the new perspective makes it easy to watch cer- 
tain features. The eyes steady themselves and 
the dizziness disappears. It is exactly what 
happens to the trembling hand when it grasps 
something, the tremors cease. 

These same little muscles, which are re- 
sponsible for dizziness, play another and very 
important part in the aviator's work. They 
are responsible for many a bad landing. To 
land well, all three points reaching the ground 
at once, calls for more than good hand and 
foot work; it calls for very good eye work. 

Distances, especially near-distances, are per- 
ceived largely by means of binocular vision. 



92 THE AVIATOR 

When Wheatstone invented the stereoscope, 
he simply allowed each eye to receive a pic- 
ture of objects similar to the impression each 
eye would receive if it were actually regard- 
ing the objects. As the tw.o eyes are in dif- 
ferent positions the view of each is different. 
My right eye sees a little more of the right 
side of a nearby tree than does the left eye, 
while the latter gets a fuller view of the left 
side of the tree. The two views together give 
the impression of depth to the tree. More- 
over, a tree just behind the one observed may 
be almost obscured, so much so that if the 
right eye is closed the left cannot see this 
second tree. But with the two eyes it is seen 
and has the appearence of being at a certain 
distance behind the tree in the foreground. 
All of this is nicely portrayed in the stereo- 
scope. We cannot go into the details of binoc- 
ular vision, but it should be stated that the 
judgment of perspective and the precise esti- 
mation of near-distance is a most important 
function of binocular vision. Inasmuch as the 



VISION IN THE AIR 93 

two pictures given to the brain by the two 
eyes are dependent upon the directions in 
w r hich the eyes are pointed, it is obvious that 
the muscles of the eyes must be all important 
in obtaining and maintaining the true direc- 
tions. Were one eye to waver the precision 
is lost. As one approaches an object the 
eyes must converge to see the object clearly. 
If they converge properly this object is seen 
as one object; other objects nearer, or fur- 
ther away are seen as doubled; a fact often 
unnoticed but one that subconsciously gives 
us a cue to distance and perspective. Lack of 
good muscle balance in the eyes means double 
images, blurring and confusion of objects and 
distances. 

It is not hard to understand, now, why so 
many "crack-ups" occur. Making a good 
landing demands a very good balance of the 
eyes. As the ground comes toward you at a 
very great speed, the eyes jump from object 
to object, focussing and refocussing very 
quickly. The height of the plane, the length 



94 THE AVIATOR 

of the glide, the place to land must be esti- 
mated. Experience and good sense are of 
course indispensable. But the machinery of 
range finding is the vision. If it fails the 
other capacities are helpless. 

To determine whether the candidate for 
aviation was equipped with a good muscle 
balance in the eyes, the Army used several 
tests. One of the simplest was a test for nys- 
tagmus. It consisted in noting carefully 
whether the eyes showed the characteristic 
twitches of nystagmus when looking ahead 
and, then, when looking to either side at an 
angle of 40 degrees. 

The ability to converge, and to move the 
two eyes together, was often observed by hav- 
ing the candidate direct his eyes upon the 
physician's finger as it was moved up and 
down, toward and from the eyes. 

Stereoscopic vision was cleverly tested by 
using the stereoscope. The ability to coordi- 
nate the movements of the two eyes and con- 
verge upon a near point was obtained 




VISION IN THE AIR 95 

by the ordinary ophthalmological tests. 
In view of the importance attributed to the 
accuracy of visual judgments, it seemed wise 
to try out the principle further. In a set of 
tests devised to detect the traits possessed by 
good aviators, one test consisted in looking 
along the curved edge of a metal plate stand- 
ing vertically upon a table. The cadet stood 
so that the plane of the plate was midway 
between the two eyes, and a double image of 
the curved line appeared as the cadet sought 
to determine where this curved edge would 
reach a scale on the table if it were continued 
downward. 1 The results of the work indi- 
cated that the better fliers among the cadets 
made the better type of judgments in the test. 
The correlation was not high, but it was sug- 
gestive of the fact that good flying and good 
eye balance go together. The ability to es- 
timate the speed of the airplane in reference 
to the ground, or to other airplanes, is also 

1 "Psychological tests for selecting aviators." Journal of 
Experimental Psychology, Vol. Ill, No. 6, pp. 409-413. 






96 



THE AVIATOR 



a matter of good visual judgment. This trait 
was studied in the same group of tests. Here, 




Front of the Eye Viewed from Within 

i. The pupil. 2. The iris. 3. The fibers of the ciliary 
muscle, to which the lens is attached. 4. The inner 
coating of the eyeball. 

too, the better type of flier averaged rather 
higher than the poorer type in the kind of 
judgments he gave. 



VISION IN THE AIR 97 

In addition to the muscles which move the 
eyeballs there is another muscle that plays a 
very important part in focussing upon objects 
which are near at hand. When an airplane 
is approaching the ground, as it comes within 
thirty feet of the objects on the surface of the 
earth, the lens of the eye begins to change its 
shape. It becomes more curved. This is ac- 
complished by the contraction of the ciliary 
muscle. The cut on page 96 shows the pu- 
pil, iris and fibers of the ciliary muscle, as 
viewed from the interior of the eye. The 
lens itself is not shown. It is biconvex and 
lies behind the pupil and iris, with its cir- 
cumference reaching nearly as far as the leaf- 
like fibers of the ciliary muscle. Its circum- 
ference is surrounded by a ligament to which 
the fibers are attached. In order to vary the 
curvature of the lens, the ciliary muscle con- 
tracts or relaxes. It can contract, relax and 
contract again in a second, or a second and a 
half, under normal conditions. When the 
aviator has been to a high altitude the depri- 



98 THE AVIATOR 

vation of oxygen may so affect this muscle 
that he will have trouble reading his instru- 
ments, or in making his landing when he 
comes down. 

The muscles which control the movements 
of the eyeball are also affected by the lack of 
adequate oxygen, and this effect may persist 
for a while after the aviator reaches normal 
air. He should always be on his guard 
against the tricks his faulty vision may play, 
when he comes down from a great height. 

From what has just been said, it might be 
inferred that muscular unbalance was the 
aviator's worst foe. That is not so. The 
muscular movements are certainly important, 
but they are second in importance to good 
vision. In reporting on airplane accidents in 
France, M. Dumas insists that pilots should 
have excellent constitutions and among the 
troubles from which no flier should suffer he 
puts the visual first. 1 It is not infrequent to 
find a man splendidly adapted for flying but 

X A. Dumas, "Les Accidents d' Aviation" p. 233. 



VISION IN THE AIR 99 

forced to wear glasses to correct a defect. 
Such men may make excellent fliers but they 
a;re always subject to dangers. Anderson 
cites a rather pathetic case. "Last summer a 
pupil with defective vision, but corrected by 
glasses, was making bad landings. He was 
on the point of being turned down but was al- 
lowed another chance. He made three at- 
tempts to land — in the first two he flattened 
out too soon and went up again, and on the 
third attempt he made a good landing. 
Yet that same evening he met his death in a 
crash. From the inquiry, no doubt remains 
that his glasses got displaced by his safety 
helmet, and his uncorrected defective vision 
was insufficient to save him." * 

There was no need for the American serv- 
ice to accept men who did not have excellent 
vision, as we had such a large number from 
which we could choose. The standard was 
set high. It called for the ability to read a 
line of print of a given size at 20 feet. This 

1 H. G. Anderson, The Medical and Surgical Aspects of 
Aviation, p. 30. 



ioo THE AVIATOR 

ability is scored 20/20. If a candidate reads 
a line of smaller type, such as one would nor- 
mally read at 15 feet, his score was 20/15, 
which indicates something better than the 
normal requirement A large number of the 
men accepted for the service had this higher 
ratio. 1. He was also tested for his near point 
in vision. The two tests gave a very good 
indication of the man's ability to see clearly 
the outlines and details of objects which a 
normal eye should detect. 

These tests did not indicate, however, 
whether the prospective flier could tell red 
from green ! Now that is a very necessary 
trait for any eye which is going to war. It 
would never do to confuse the colors of Eng- 
land and Ireland, and the red-green confusion 
is the most common in all color-blindness. 
One does not realize how many objects are 
red, or green; or have those colors in them, 
until he listens to a color-blind friend de- 
scribe the world about him. What a man 

1 Air Service Medical, p. 70. 



VISION IN THE AIR 101 

would do as an observer of terrain, troop 
movements, hostile planes or signals, with 
such a defect can well be imagined. 

It happens that a large percentage of men 
normal in every other way are defective in 
color vision, about five in every hundred. 
Curiously enough women escape this defect 
more frequently than men, about one in one 
hundred are color blind. Many theories are 
advanced to explain this deficiency. The ret- 
ina of the eye is that part of the optic 'nerve 
which expands and covers the rear portions of 
the eye, upon which the light falls, as it 
passes through the pupil. This nerve is com- 
posed of thousands of fibres. These have 
their endings in the retina in the shape of 
minute rods or cones. When colored light 
strikes the rods, a sensation of light alone is 
given, but when it strikes the cones a sensa- 
tion of color is given. As there are more 
cones than rods in the back part of the eye, 
naturally one sees colors best when the light 
from colored objects fall on that section. The 



102 THE AVIATOR 

minute area where the rays are converged 
by the lens of the eye and where the best 
vision is obtained is composed entirely of 
cones. Far out on either side are rods only; 
and in those areas we are all color blind. 
That is why a colored light that strikes far 
to one side of the eye instead of in the center 
is seen only as a white light. This is the 
cause of many accidents. Red signals may 
be flashed in such a way that the eye catches 
them as merely white lights. It happens 
that blues and yellows are seen much further 
out to the side than reds and greens. It also 
appears that many animals are partly color- 
blind and some completely so. Nocturnal 
animals have need of rods rather than cones. 
So we find the owl with rods only. That is 
also true of the mole. Where there is a need 
for color discrimination, as in a bird, to de- 
tect colors in the plumage of other birds, 
there is always good color vision. Accord- 
ing to one theory the remote ancestors of the 
human race saw only objects and no colors, 






VISION IN THE AIR 103 

gradually they acquired a blue-yellow vision 
and later the red-green in addition. Cases 
of red-green color-blindness would repre- 
sent an atavism, or reversion to earlier types, 
in which this higher development of the color 
vision was absent. 

Some experimenters believe that the color 
tests ought to be the most stringent for the 
aviator as it is through this sense that the 
judgment as to the exact distance to the 
ground, when about to land, is rendered ac- 
curate. Correct judgment in this respect in- 
volves an intact color sense, because the va- 
rious greens and browns of the landing place 
are often refracted through a bluish mist 
which obscures distance. 

In night flying the relative values of colors 
change. The reds suffer the greatest alter- 
ation and the blues the least. Some red ob- 
jects appear black in a very dim light. It is 
unsafe to trust color vision for reds in a dim 
light. 

One of the most trying experiences in night 



to 4 THE AVIATOR 

flying during the war was the glare from 
rockets and flares. The Germans were cred- 
ited with using a light which contained a high 
per cent of the violet rays. These rays are 
the most active chemically upon the photo- 
chemical substance of the retina and cause 
the greatest blinding effects. There seems 
to be some difference in the ability to recover 
from such glares. Those who are happy 
enough to possess quick recuperative faculties 
are the better endowed for night bombing. 

Glares are by no means the only things 
which exact a penalty from the aviator's eyes. 
When the sun shines on white clouds or he 
has to fly with the light in his eyes, the strain 
is very hard to bear. The wind is very try- 
ing on the eyes, and if there are flecks of oil 
flying there is danger of injury to the eye and 
to the man. 

Occasionally an oil lead breaks and 
the oil may strike the eyes. Goggles should 
be worn which are tinted to take out the 
rays at the violet end of the spectrum but 



VISION IN THE AIR 105 

which also have a very high percentage of 
light transmission. 

The most interesting factor in vision is not 
the eye but the brain. Some familiar illus- 
trations will make the division of labor be- 
tween the two very •clear. You see this line 
of print. Your eyes move over these words in 
jerks, not in a uniform movement. During 
the pauses you read these words, during the 
quick movements you see nothing. That is, 
you do not get a blur of letters every time 
your eyes move over the lines. If you will 
move your finger slowly and uniformly under 
the line and let your eyes move with it you 
will discover at once that the letters blur. In 
the habitual act of reading no such 
blur occurs because the brain has acquired 
the habit of using only the clear images, which 
consciousness uses in reading. Every day 
experiences give all sorts of illustrations of 
these habits of perception. Look at a letter 
"s," notice that the upper and lower loops 
appear to be about the same size. Turn the 



106 THE AVIATOR 

letter upside down. The upper loop was the 
smaller one in the original position, but we 
have formed the habit of seeing them as 
though they were symmetrical. The same is 
true of the figure "8." One can acquire all 
kinds of habits. Glasses may be worn which 
turn the world upside down. Gradually it 
will be turned right side up again as we form 
new habits. Tinted glasses make the world 
look colored until we get the habit of cor- 
recting the colors ; then we forget we have the 
amber glasses. To the marksman who has 
closed the left eye when aiming there is con- 
siderable confusion when he sights with both 
eyes. After a little practice he ignores the 
greater part of what the left eye sees. Those 
who use the microscope can see the magnified 
objects with one eye, or the papers alongside 
of the instrument with the other as they shift 
the attention. 

The difficulty of determining what sort of a 
world lies beneath the airplane is well illus- 
trated in the picture of a road winding through 



VISION IN THE AIR 107 

the Italian Alps. Mountains are seen by the 
man on the ground with a sky-line which out- 
lines their heights. No sky-line appears to 
the aviator who looks down from the sky. 
He cannot see one mountain set off against 
another as they appear from the sides. He 
sees them as the shadows from their sides 
outline them. What their relative heights 
may be he must learn by inference. Notice 
how the road writes a letter "M" as it threads 
its way about the mountains. It is almost im- 
possible to determine which leg of the letter 
rests upon the higher ground. We are sure 
the road is not level, and we are sure that its 
curves were built to overcome the grades. 
But how do the grades lie? The eyes must 
acquire new habits in estimating the heights 
and the slope of mountains when seen from 
this unaccustomed angle. 

Niagara Falls gives a more remarkable 
illustration of the appearance of familiar ob- 
jects from the birds' point of view. The fa- 
mous Falls roaring hardly four hundred feet 



io8 THE AVIATOR 

beneath the airplane are difficult to see. One 
has to search the picture to detect their line 
of fall. Even then the water above and be- 
low the falls does not appear to be at any 
very distinct difference in distance from the 
observer. Indeed, one has to look closely 
to decide just which way the water is flowing. 
Perhaps he will determine this point by rea- 
soning rather than by recognizing the char- 
acteristic lines in the water, which indicate 
the direction of its flow. 

Until habits of seeing objects from the air 
are formed, it is necessary to reason about 
them. Recognition depends on this reason- 
ing. The height of an object must be rec- 
ognized by the sort of a shadow it throws. 
One of the tricks of camouflaging lay in the 
ability to deceive the hostile aviator with 
shadows. If an object threw no shadow on a 
sunny day, the aviator naturally inferred that 
it was either very low or level with the ground. 
By building a hangar with sides which sloped 
to the ground and threw no shadows it was 





'Photograph from Underwood & Underwood, N. Y 



Niagara Falls from an Airplane at 350 Feet 
Notice the difficulty in detecting the line of the Falls. 



VISION IN THE AIR 109 

practicable to deceive the bomber flying at 
any moderate height. Then, too, the way 
objects upon the ground reflect light furnishes 
another set of cues the aviator must use in 
recognizing the world below. After a rain 
the lighter brown field of earth will be drier 
than the darker. The corn field will be a 
different shade from the grass lawn, 
though the texture of the plots of green may 
seem much the same. And the eye must be 
trained for texture differences as well as light 
and color differences. Here, again, the cam- 
oufleur deceived the aviator. By selecting 
materials which reflected the light and as- 
sumed the texture at a distance, like the ob- 
jects of nature, it was not hard to trick the air 
observer. 

The eye cannot detect color patches at a 
great distance, though the patch itself may be 
seen. When a blue and a yellow patch are 
separated by an irregular line they blend into 
a gray, if they are rightly proportioned; or 
into a yellowish-gray or into a bluish-gray, 



no THE AVIATOR 

if the proportions are not correctly balanced. 
Such tricks the aviator must be prepared for 
by learning from experience. Fortunately, 
Nature comes to his aid and consciously as 
well as unconsciously he builds up habits of 
seeing his world anew. Quite consciously he 
may build the habit of seeing the meadows, be- 
tween which a river runs, slope toward the 
river. Geography teaches that. Uncon- 
sciously he may acquire the knack of detecting 
the slope of the grassy fields by the color 
shades. 

Some tricks the new angle of vision may 
play upon him should be studied at the be- 
ginning of his career. "A pilot is inclined to 
overestimate distance in bad light, in mists, 
and when the field and background are the 
same dull colour. He will underestimate dis- 
tance when the light is very good, or when 
he is landing with the sun behind him." 1 

One of the most difficult things to accom- 
plish is the right estimate of distance when 

1 McMinnies, W. C, Practical Flying, p. 169. 



VISION IN THE AIR in 

trying to make a landing on perfectly smooth 
water, or on broad fields covered with snow. 
The difficulty comes from the loss of one of 
the cues we always use in gauging distances, 
namely, objects for comparison. Everyone 
has noticed how hard it is to guess the dis- 
tance to the surface of a smooth lake, when 
you look down forty feet. If you can see the 
side of the boat, or wharf, you can estimate 
fairly well, for then you have objects to 
measure with; but without these you natur- 
ally resort to objects floating on the water. 
If these are familiar you guess your distance 
by their size. If there are ripples you guess 
on the basis of their height, or distance apart. 
If the ship is moving, the speed at which the 
objects pass helps the estimate of distance. 
But when there are no objects floating and no 
ripples running you are without cues. That 
is the situation in the hydroplane over a 
glassy sea, and in the airplane hovering over 
an expanse of level snow. 
Occasionally, our habits of perception play 



ii2 THE AVIATOR 

tricks on us. One of the most common il- 
lusions is that the train is moving, when 
the train beside the car window moves; or 
to feel that you are in motion, when lying 
on your back watching the clouds above 
scurry across the sky. We have deep-seated 
habits of estimating motion in relation to our 
positions. Into these habits must be woven 
the habit of thinking of motion not in terms 
of the earth but of the air! One of the dif- 
ficult things is to acquire the knack of think- 
ing of the ship's motion in terms of wind. 
Nothing has ever seemed more incongruous to 
me than the sight of a woods over which we 
hung in a high wind during my first flight 
To be rushing through space and standing 
still at the same moment is a bit confusing. 
Among the beginners the habit of thinking of 
the motion of the airplane in terms of the mo- 
tion of the objects beneath is one of the most 
dangerous. Into the perception of motion 
must come the "feel of the ship," the sense of 
passage through the air, not over the earth. 



VISION IN THE AIR 113 

An observant cadet summed the whole mat- 
ter up by remarking that in the air the poet's 
words have a peculiar meaning, "things are 
not what they seem." 



CHAPTER VI 
OTHER SENSES 

The "Five Senses" as they were known to 
our fathers and as they live in popular litera- 
ture are commonly supposed to be all the 
senses one possesses. Now and then the novel- 
ist calls in the mystic "sixth" sense. So handy 
has this sixth sense become that we are not 
surprised to find it used to explain the aviator's 
sensibilities. Of course, there is a sixth sense 
and a seventh and an eighth and a number 
more, but they are not at all mysterious. 

In the skin alone there lie four different 
sorts of minute nerve endings. They are in 
the shape of little bulbs, spindles, of simply 
free-spreading nerve endings. If one takes 
a stiff hair and presses gently on an area of 
the skin upon the inner forearm, he finds some 

of the slight touches are felt and some are not. 

114 



OTHER SENSES 115 

Where they are felt there lies a touch-bulb 
just beneath the surface of the skin. Heat 
and cold spots may be located by using a 
chilled or warmed wire in the same manner. 
And the spots sensitive to a pricking from a 
sharpened bristle may be found by the same 
sort of exploring. These four: touch, pain, 
heat and cold are the four cutaneous senses. 

No one in taking hold of a stick is aware 
of the various cutaneous sensations unless he 
has practiced sorting them out. They blend 
into a characteristic feeling. The stick is 
cold, hard and splintery, all of this informa- 
tion comes through the several senses, but it 
is blended into the perception of the sort of 
stick which is grasped. 

Beneath these surface senses are deeper- 
seated senses, which give us the sensation of 
pressure in the flesh beneath the skin, or of 
pain there. Similar to these are the muscular 
sensations. Everyone knows these from fa- 
tigue, or from kneading the muscles, or in 
simply tensing them. Along with these go 



n6 THE AVIATOR 

the sensations of the joints in making move- 
ments. The combination of the muscle sen- 
sations and those of the joints is known as a 
kinaesthetic sensation, that is the sensation 
of a movement. It is the kinaesthetic sensations 
we use when we swing the golf club in ad- 
dressing the ball. With each swing we try 
to get just the sensations needed to bring the 
club against the ball. When we get the right 
feeling we make the stroke. Getting the feel- 
ing consists in trying out our kinaesthetic 
senses. 

There are many places where the cutaneous 
and the kinaesthetic senses play an inconspic- 
uous but important part. The nicety with 
which the celloist runs his hand down the 
finger-board of his instrument and stops ex- 
actly where he wishes in order to give a cer- 
tain high note is a result of well-trained cu- 
taneous and kinaesthetic perceptions. Like- 
wise the precision with which the aviator 
moves his controls is due to the same senses. 
His joy-stick goes just the amount of distance 



OTHER SENSES 117 

needed to bring his plane to a level, as it seeks 
to dip, or to rise in choppy air. When the 
machine loses air-speed, he feels it at once in 
the loss of resistance in the controls. They 
become "sloppy," to use his own favorite ex- 
pression, and at once he throws the stick for- 
ward and gains headway with a steep glide. 
How far forward will he thrust the stick? 
That depends entirely upon what his kin- 
aesthetic and cutaneous senses tell him. 
Should he lose these senses he would have to 
depend upon his eyes to measure the move- 
ments of his hand. The aviator must get the 
sense of pressures and movements from his 
stick and rudder as they respond to the air 
and to his own efforts. He must keep some 
of these sensations in mind. Machines tend- 
ing to turn with the propellor torque call for 
a constant correction with the rudder. With- 
out carrying the fact in mind, the aviator 
must have such facts at his finger tips and his 
toes ends for constant reference. A right 
turn will call for different rudder pressure 



u8 THE AVIATOR 

from a left; and if it is a sharp turn the play 
of the stick must be nicely timed with the 
rudder, — as nicely as the fingering of the 
violinist times with the bowing. In both 
cases it is the keen sensibilities which make 
such nice coordinations possible. 

There is, of course, the sense of hearing 
which guides the violinist along with the 
senses mentioned. No such important role 
is played by hearing in the aviator's work. 
Nevertheless, there are not a few men who 
have called my attention to the fact that among 
the best fliers on the field were several musi- 
cians. Explanations for this were numerous, 
such as: the musician is a "live wire," he has 
"the temperament" or "he catches the sound 
of the motor and the wind," or "his hands are 
sensitive and trained to nice movements." 
Usually there is a belief that the ear trained to 
catch different tones is a distinct advantage 
to the flier. He has the habit of separating 
one sort of sound from an ensemble of sounds. 
He has the knack of attending to it and it 



OTHER SENSES 119 

alone. This is a knack every good mechanic 
and pilot must acquire at some time. 

One thing, however, every flier learns about 
his ear. It must be considered when he 
passes quickly from one level to another. 
Air pressure lessens as one rises and increases 
as one descends. This shifting of pressure on 
the drum of the ear is quickly discerned and 
he must form the habit of swallowing to 
equalize the pressure. In the high altitudes 
the air is so thin that sounds do not carry 
easily. Balloonists have to shout to each 
other to be heard. If one is not aware of 
this, he imagines his hearing is failing him, or 
that his engine is not running well. 

The constant roar of the engine is very 
trying to some ears. That, with the rush of 
the air and the change of the pressure, often 
gives one the unpleasant feeling of dulled 
hearing when he reaches the ground, the 
feeling of "having your head in a barrel." 
It seems that the higher notes are not so easily 
heard when one's ears get into this condition. 



120 THE AVIATOR] 

The low tones do not appear to be affected in 
the same degree. 

A group of sensations which arise from 
stimulations within the body is known as or- 
ganic. These sensations from the viscera and 
the vital organs also contribute to the avia- 
tor's information. In this case it is informa- 
tion about himself and not about his surround- 
ings, and for this reason he should not ignore 
them. When the attention is upon the con- 
trol of the ship and upon the direction of its 
course, one is apt to neglect the quickened 
heart beat, or the quickened breathing, which 
give warning of high altitude and possible 
collapse. Indeed, it is hard to persuade the 
average aviator to turn his attention to the 
signals coming from his own internal ma- 
chinery. Some of the best fliers have met 
with disasters because they ignored the warn- 
ings of their physical machinery. It is an 
old adage that a man is a fool, or a physician, 
by the time he is forty. Only a fool could 
live to that age and not learn enough about 



OTHER SENSES 121 

his constitution to attempt some care of it in 
an intelligent way. With the young aviator 
the situation is not different. He should 
watch his physical signals to learn what they 
mean in order to keep himself fit to fly. 



CHAPTER VII 

THE FEEL OF THE SHIP 

Every science and, indeed, every sport has 
its own vocabulary. About the first thing to 
do when studying either is to learn its lan- 
guage. Mistakes are unavoidable if you can- 
not tell what a word may mean to the scientist, 
or sportsman, who uses it. Who could guess 
that a "rock" to the geologist is "any material 
constituting a portion of the earth, whether 
hard or soft"? Such an idea must be kept 
strictly within bounds, for if it got beyond 
geology into poetry it would work havoc. No 
one could tell what Fitz James meant when 
he shouted "Come one, come all! This rock 
shall fly from its firm base as soon as I." If 
the "rock" were light sand, James might have 
disappeared with the wings of the wind. If 
it were granite it would have required dyna- 

122 



THE FEEL OF THE SHIP 123 

mite to move him. Geology would require 
that the warrior be a little more specific. 

Aviation, as a science, takes some peculiar 
liberties with familiar words. "Dope" in 
popular usage has a rather sinister signifi- 
cance. In aviation circles it is nothing more 
dangerous than a varnish for the fabric of 
the airplane, A "crack-up" in ordinary lan- 
guage would signify a slight mishap; with 
the aviator it may mean a ride in the ambu- 
lance. Such foreign terms as "nacelle," "fu- 
selage," "aileron" or "volplane" are easily 
naturalized. It is rather the peculiar twist 
given to familiar expressions that causes the 
perplexity. Often it is not hard to guess what 
is meant. When a machine "pancakes" nat- 
urally it slaps the ground flat, but what hap- 
pens when it "zooms"? The lever controlled 
by the hand is a "joy-stick." Who could guess 
the origin of that? It seems a Mr. Joyce in- 
vented the lever and a slovenly pronunciation 
did the rest. This bit of information I ac- 
quired by persistently asking questions of avia- 



124 THE AVIATOR 

tors, mechanics, and engineers until I chanced 
upon an engineer who happened to know. 

Not so successful was my endeavor to learn 
what is meant by "the feel of the ship." 
Everyone who had ever piloted an airplane 
seemed to need the expression. It is used 
constantly. Instructors cannot discuss their 
pupils without using it, and cadets in the pro- 
cess of acquiring their wings seem to know 
what it means. Occasionally some one 
would reward me by saying, "You can't 
describe it any more than you can any other 
feeling. You got to get it. See?" As I had 
only been in the air once before I began har- 
assing my fellow officers for knowledge. I did 
not "see." I tried to gather all the infor- 
mation that an outsider could get. One very 
able instructor told me that he had a cadet, 
of high standing in college and ground school, 
to instruct in flying. The cadet understood 
everything about the science of flying, but 
could not get the art. "He can't get the feel 
of the ship," exclaimed the instructor. "On 



THE FEEL OF THE SHIP 125 

the ground he is a whizz, but in the air he is 
harmless, perfectly harmless!" That "harm- 
less" was a free use of the word ; for this bright 
cadet nearly killed two of his instructors while 
trying to get "the feel of the ship." Other in- 
structors were less picturesque, but equally 
positive, in describing the incapacity of the 
cadet who could not acquire the "feel." They 
all agreed that, whatever other acquirements 
a pupil might have, he could not be a reliable 
flier until he had this indispensable one. 

Occasionally, I found a man who had been 
flying one of the very large airplanes by use 
of instruments. He rather scouted the idea 
of the primary importance of the "feel." 
His notion was that the good pilot is a good 
mechanic and navigator. But the men who 
fly solo do not subscribe to any such heresy. 
Simply to change from one type of ship to 
another causes the man trained in a given 
model no little trouble. He has to get the 
"feel" of the new craft. One young lieuten- 
ant whose knowledge of airplanes was largely 



126 THE AVIATOR 

from the slow flying type took a high powered 
machine out for a trial spin. When he 
thought he had her "f eel" he tried a roll. In- 
stead of making one revolution he made three 
before he could bring his ship to a level. 
Each type of airplane seems to have its own in- 
dividuality. The good pilot readily acquires 
a new attitude, but it is based on the feel of 
the ship. 

So important is this ability that the "Notes 
and Rules for Pilots of the Signal Corps" 
makes this emphatic rule: "Never continue 
flying when a machine feels uncomfortable to 
you or you feel something is wrong." 

A major who had flown many thousand 
miles informed me that he knew instantly 
when his ship was not flying right. "Your 
controls tell you," he exclaimed, "Why they 
shout it to you!" How, he could not tell, 
but he was positive that he felt it. 

Most striking of all is the characteristic this 
acquirement has of varying from time to time. 
It is not a stable possession. When a man 



THE FEEL OF THE SHIP 127 

goes "stale" his flying becomes poor. He 
does not sense his ship's motions and anticipate 
her movements as he should. Moreover, the 
feel of the ship is lost in large measure when 
one does not ride in an airplane for a while. 
How long, is a debated question. An officer 
who had charge of a field where the men go 
up daily, in all w r eathers, declared that he 
never let one of his men go up alone, who 
had been out of an airplane for two weeks. 
To do so was to invite an accident. Likely 
enough a man might be out of an airplane two 
months, or six, and make a successful flight, 
but in the long run the man who does not 
fly for fourteen days "loses his edge," and may 
easily crash his craft in landing, or getting 
off. It is the average that counts with this 
flying officer not the striking exceptions, and 
his average is the expression of a number of 
years of practical experience. 

Some aviators have frankly confessed to me 
that they know their feel of the ship tends 
to disappear after a two weeks' vacation. 



128 THE AVIATOR 

Nevertheless, they are often willing to go 
"solo" as soon as they return to the field. A 
careful flier realizes that he must fly dual be- 
fore he trusts himself alone after a vacation. 
In one case an instructor had been away for 
only ten days. In trying his hydroplane, solo, 
in quiet air he found his turns were badly 
done and he was actually becoming dizzy. 
Both the finesse of his control and his tol- 
erance for vertigo had suffered from those 
few days without practice. 

Though fliers cannot agree upon how long 
the feel of the ship stays with them or what 
it is, they do seem agreed upon the difficulty in 
explaining it. After listening carefully to a 
number of them, it occurred to me to take 
the advice of the officer who remarked that 
the only way to understand it is to get it. 
After a few lessons in the air, I found it steal- 
ing in upon me. As a psychologist it was 
somewhat more recognizable to me than it 
might have been to one who has not made a 
practice of analyzing his sensations and re- 



THE FEEL OF THE SHIP 129 

actions. Indeed, it is not an unfamiliar ex- 
perience. Many others are quite like it, 
though I know of none which combines so 
many elements. It is nothing more than the 
experience of receiving a number of sensa- 
tions of different quality and intensity and re- 
sponding to them by certain actions, each 
action being checked up by a consequent sen- 
sation. The experience is one of a contin- 
uous sensation- reaction-sensation character. 
Of course, that describes all sorts of experi- 
ences,— riding a bicycle, sailing a boat, skat- 
ing, swimming, or, indeed, walking. In what 
lies the difference? For surely there is a dif- 
ference between walking and flying! Three 
things make that difference. First, an ob- 
vious one, flying is a new and strange experi- 
ence. Second, many more senses are engaged 
and responses required than in any usual oc- 
cupation. Third, the senses engaged are ones 
we do not customarily use to so great an ex- 
tent and degree. 

Before attempting to unravel the sensations 



1 3 o THE AVIATOR 

and reactions of the aviator, let us examine 
some simpler experiences, and on the basis of 
their analysis try to understand the "feel of 
the ship." 

One of the simplest examples of "feel" 
that we all know is the group of sensations 
which guides us in acquiring skill with tools. 
It is the "feel" of the chisel, the plane and the 
saw that directs the hand and aim, as the in- 
struments cut with the grain or across it. No 
one thinks of the slight tactual sensations, or 
the muscle, tendon, and joint sensations as 
such. Instead, he thinks of his tools as part 
of himself. He seems to project himself into 
the end of the chisel as it moves along a sur- 
face or an edge. The sensations are all in- 
terpreted in terms of what the chisel is do- 
ing as it slips under the wood, not in terms 
of pressure on the hand, or strain in the mus- 
cle. Thus, the blind man thinks of the end 
of his cane as a prolongation of his arm. He 
feels the smooth and the rough pavements, he 
feels the firm and soft ground. It is the 



THE FEEL OF THE SHIP 131 

ground he thinks he feels not the stick. This 
trait is often called "projecting" one's sensi- 
bilities, for the sensibilities seem to be in the 
instrument rather than in the hand. 

Rowing furnishes a good illustration of 
this sort of an experience. After some work 
with the oars one begins to have his sensa- 
tions projected to the blades. He feels the 
surface of the water almost as though his 
hands were touching it. If the craft is a light 
shell so that every little wave is felt, the rower 
begins to feel the surface of the water in both 
the oars and the shell. He recognizes the 
edge of a cross current, the first swelling of a 
wave, the roughing of the surface by a "cat's 
paw," as readily as though his body were in 
the water. He has a sense of being one with 
the craft. He has "the feel of the ship." 
Some men never get this nice sense of a shell's 
response to the water and to their own actions, 
and they never become oarsmen. 

Not only do we ignore sensations as such 
when they come to us from the things we are 



i 3 2 THE AVIATOR 

using, but we ignore also the sensation we re- 
ceive from our own movements. This, of 
course, is the result of practice. At first we 
are quite conscious of them. Another illus- 
tration will make this clear. In learning golf 
everyone is quite conscious of the feeling of 
the stick as he tries to acquire the correct hold. 
He is told to think of the muscular sensations 
as he learns how to swing his club. This is 
necessary in order to acquire a full swing and 
to adjust it to the length of the club and the 
weight. Moreover, one has to think of the 
turn at the waist and the balance of the 
weight on the legs. At first the attention is 
pretty well occupied with these sensations, 
which guide us in getting the stance and the 
stroke. Later, as the movements have become 
habitual, the attention carries them so lightly 
that one is not aware of them until something 
goes wrong. If a club is too heavy, or badly 
balanced, the "feel" of the club in its swing 
tells us there is something wrong. Ordinarily 
the attention is upon what we are doing not 



THE FEEL OF THE SHIP 133 

how we are doing it We give little thought 
to the sensations of movements and a great 
deal to the little white ball and the landscape. 
Such a shift of the center of one's interest and 
attention goes on in everything that we learn 
to do. As actions become habitual we lose 
track of the means by which we made them 
become habitual. No wonder it is hard for 
the old pilot to tell the cadet just how he 
feels a "bump" coming and what he does to 
keep the airplane level. 

Some forms of learning suffer more than 
others in this particular. We can remember 
how we learned the things we know but not 
the things we do. How difficult it is to re- 
member the way the laces are manipulated in 
lacing the shoes, or the necktie in making a 
bow! Usually we have to do the thing to 
bring the sequence of motions into mind at all. 

With these reminders of our troubles in 
analyzing simple performances, let us revert 
to the pilot's trouble in explaining how he 
flies level. A bump in the air starts to raise 



i 3 4 THE AVIATOR 

his left wing and pull his craft out of the line 
of her course, but it does not do it. With the 
rising of the left side of his seat the pilot gets 
a group of sensations; increased pressure on 
left side of the seat, a shift of his balance and 
a new tension of muscles. To these sensa- 
tions he gives little thought, they mean "bump 
under left wing." Over comes the joy-stick 
to the left, down goes the wing. He did not 
know he did it! Perhaps the air bump 
sent an outrider in the nature of a puff of air 
to the pilot's left cheek. If so, he had his 
controls ready to keep the ship steady when 
the bump developed. Again he did not no- 
tice what he did. His signals and responses 
are as vague to his mind as those we receive 
and make in riding a bicycle. 

When the list of signals the airman uses is 
totalled up it is certainly impressive, not only 
for its size but for its unique features. A par- 
tial enumeration of these will give some idea 
of what goes into the "feel of the ship." As 
he takes off from the flying grounds his motor 



THE FEEL OF THE SHIP 135 

gathers speed with the opening of the throttle. 
There is a change of intensity and pitch in 
the sound of the motor. He knows how these 
should vary with the changes of the throttle. 
These are the first signal and response. As 
the machine gathers speed he feels the increase 
in wind pressure, and the increase in the vibra- 
tions from the ground and he sees the speed 
with which the ground sweeps by him. 

These signals for him to raise his elevators 
and rise may be deceptive. If he is going 
with the wind, the ground may be flying past 
at a rate that seems to justify rising but he 
may not have enough air speed. This misin- 
terpretation of a usual cue has resulted in 
many a crash. If he rises into the air the 
bumping from the wheels upon the earth 
ceases, there is the feeling of being supported 
by the air and also a tautness in the con- 
trols, which means the machine is responding 
to the pilot's direction. From this time till 
he returns to the ground the feel of the ship 
is ever present. 



136 THE AVIATOR 

If the air is choppy, the habits just men- 
tioned keep the ship level and true to her 
course. As he rises, the direction of the wind 
changes, the pilot feels it and corrects for his 
driftage. Each moment is full. With eyes 
roving* from the ground to the cowl, to the 
horizon, then to the object by which he makes 
his course, with ears alert to the whistle of 
the wind in struts and wires, to the roar of 
the motor, with the mind receptive to the play 
of the wind on the cheeks, to the seat's pressure 
upon the legs and back, to the vague sense of 
balance, he is constantly receiving the signals 
which are constantly being translated into a 
pressure on the rudder, now to this side, now 
to that, with an allowance for the propeller 
torque, a pull of the joy-stick to keep her 
nose up, or a push to get gliding speed, and a 
turn to right or left, suiting each to the move- 
ments of the rudder. The airman's nervous 
system is alive with currents to and from his 
higher nerve centers. With habituation to 
the work the highest center is freer for thought 



THE FEEL OF THE SHIP 137 

about other things, but never is the man con- 
trolling an airplane released from a constant 
and multifarious interplay of nerve activities. 

True, a well-made machine and a still day 
may leave the pilot with a feeling of "nothing 
to do," he may claim he drowses and that the 
ship will fly itself, and it does ; just as a piano 
plays itself while the artist carries on a conver- 
sation, or as the bicycle holds the expert while 
he shaves. Habits are deceptive things! 

Illustrative of the nerve energy engaged in 
flying is the type of things flying men do when 
enervated. Stale fliers show a ragged form. 
They think they are doing well, but they may 
be carrying one wing down, or climbing too 
steeply, or showing bad judgment in land- 
ing, — where so many signals and responses 
are needed. Deprivation of oxygen gives a 
fatigue which results in a loss of those fine 
coordinations in control that make for good 
flying. In short, anything that interferes with 
the fullest functioning of the nervous system 
may rob the flier of the sensory cues he needs 



i 3 -8 THE AVIATOR 

to guide him, or of the quick and accurate re- 
sponses to these cues. No wonder that the 
flight surgeon was alive to the dangers of a 
"hop" when a cadet had just gotten back from 
a spree, or was stale, or had been sick. Good 
flying calls for a wonderful interplay of nerve 
currents. The nicety and precision and the 
great number and variety of these constitute 
the peculiar demand of the art of aviation. 
Let the flier stay away from his controls for 
ten days and he is out of practice. His elab- 
orate system of receiving stimuli and translat- 
ing them into actions begins to lose some 
factors, or they fail to fit. His tolerance for 
turning has faded. His quick attention to 
faint stimuli must be re-aroused. The edge 
must be returned, it is blunted by a few days 
with no practice. 

There is no new thing under the sun. 
Violinists long since discovered the need of 
keeping their art alive by daily practice. 
Otherwise one loses those fine sensibilities by 
which the hand and the ear do their best. No 



THE FEEL OF THE SHIP 139 

juggler can ignore the daily trick, or the hand 
and the eye lose the fine adjustment to each 
other. How much greater is the demand upon 
the aviator! Every sense and every movement 
must be keyed together. Great aviators are 
great artists and not the least of their genius 
lies in their "feel of the ship." 



CHAPTER VIII 

OXYGEN AND EFFICIENCY 

SOME two hundred and fifty years ago, o * 
Robert Hooke performed a crude experiment 
before the Royal Society. He removed the 
ribs and diaphragm of a dog and kept the 
animal alive by blowing air with a bellows 
into the windpipe. Death, he pointed out, was 
the result of an insufficient supply of air. A 
few years later John Mayon claimed that 
what he called the "Spiritus Nitro-aereus" 
was the peculiar substance in the air which 
made wood burn and supported life. With 
the passing of the centuries and the great re- 
finement in chemical methods, it is possible 
now to measure the amount of oxygen the 
various tissues of the body use. Thus the 
amount of oxygen consumed by the heart per 

gram weight per minute is between four and 

140 



OXYGEN AND EFFICIENCY 141 

eight hundredths of a cubic centimeter. Dif- 
ferent tissues call for different amounts of oxy- 
gen, and the greater their activity the greater 
their demands. Shut off the supply and star- 
vation begins. One thing is indispensable to 
"every beast of the earth, and to every fowl of 
the air, and to every thing that creepeth upon 
the earth,"- — oxygen. 

Only a certain amount of oxygen in the tis- 
sues is necessary. The system will not absorb 
more than it requires. If one receives a sur- 
plus, he returns it to the air. However, the 
difficulty the aviator experiences is not with 
excess, but depletion. This results from the 
lessened air pressure due to altitudes. Gases 
in contact with a liquid either unite chemi- 
cally or dissolve. Some of the dissolved mol- 
ecules escape from the liquid and become gas 
again. After a while, there is an equilibrium 
formed between the molecules being dissolved 
and those escaping; and this balance depends 
upon the pressure of the gas upon the liquid. 
Decrease the pressure and there are fewer gas 



142 THE AVIATOR 

molecules dissolved. This is what happens 
in the exchange of molecules between the air 
and the blood, as one rises in altitude. The 
ratio of oxygen to nitrogen remains the same, 
about one to five ; but the atmosphere is lighter, 
consequently the blood in the lungs obtains 
less oxygen. 

Oxidization occurs in the cells of the body 
tissues; and the amount of oxygen passing to 
the cells depends on the difference in pressure 
of oxygen in the tissue and the blood. The 
oxygen will diffuse to the places of low pres- 
sure. The oxygen is carried in the hemoglo- 
bin of the blood stream and is passed through 
the walls of the capillaries of the tissues. 
Anything which enlarges the volume of the 
blood, such as dilation of the blood vessels, 
or a quicker heart beat means an increase in 
oxygen supply. Nature uses these means to 
increase the supply. Every mountain climber 
should have a good record for heart rate and 
blood pressure. However, the simplest way 



OXYGEN AND EFFICIENCY 143 

of increasing the oxygen supply is by increas- 
ing the amount of air taken into the lungs. 
These three devices are automatically used 
by every one whose system tries to compensate 
for the deprivation of oxygen. This is 
brought about by the carbon dioxide in the 
blood which passes through the respiratory 
center in the brain (medulla). The carbon 
dioxide is increased as the oxygen is decreased 
and it acts as an excitant upon the centers 
in the brain which control the actions of the 
heart and lungs. With the quickened, or 
deepened, breathing and the quickened heart 
action more oxygen enters the blood stream 
and the balance is restored once more. It 
should be said also, that in this same part of 
the brain is the center which controls the size 
of the blood vessels and, therefore, the amount 
of blood which may flow to any part of the 
body at any time. Should these centers fail 
in their response to the stimulus from the 
blood, the result would be a failure to com- 



i 4 4 THE AVIATOR 

pensate with more blood for the lack of rich 
blood. This could only mean deterioration 
of the tissues and eventually death. 

In the "rebreathing tests," which will be 
explained later, it was found that many men 
did not breathe more rapidly as the oxygen was 
denied them, but they would breathe more 
deeply. That is the usual reaction to oxygen 
want. The heart increases its beat slightly 
at first and then more rapidly as the depri- 
vation of oxygen increases. "A delay in the 
first appearance of acceleration of the heart 
rate may be due to an insensitive cardiac 
brain center and an early response may indi- 
cate a mechanism very sensitive and respon- 
sive to any decrease in available oxygen." * 
An increase of fifteen to forty beats in the 
heart rate when the per cent, of oxygen was 
diminished from the usual 21 down to 7.5 or 
6.5 was considered a good reaction. If this 
acceleration did not occur, the experimenters 
knew that there was some other compensation 

1 Air Service Medical p. 175. 



OXYGEN AND EFFICIENCY 145 

occurring, such as a concentration of the 
blood, or increased breathing; otherwise the 
subject of the experiment would fail to with- 
stand the oxygen starvation. An increase of 
fifty to seventy beats means too great a strain 
on the system and occurs only in men who do 
not tolerate well low percentages of oxygen. 
In such men compensatory reactions may fail 
to occur. "So far as the response in pulse rate 
to decreasing oxygen is concerned, it, there- 
fore, becomes possible to rate the reaction as 
poor, good, and excessive. A poor, or an ex- 
cessive, heart response should disqualify the 
candidate for very high altitudes; he should 
only ascend to moderate heights." * 

Each beat of the heart has two aspects, the 
contracting of the muscles which drives the 
blood forth known as the systole, and the di- 
lation of the heart in relaxation known as the 
diastole. The pressure of the blood in the ar- 
teries of course is greater as it is forced by the 
heart beat. This is the systolic pressure. 

1 Op. cit. p. 175. 



146 THE AVIATOR 

The pressure in the arteries at the end of the 
diastole of the heart is the lesser pressure and 
is known as diastolic pressure. It will be seen 
that these two may not increase and decrease 
together. In fact they do not do so in the 
changes in blood pressure due to diminution 
of oxygen. In the best type of response to 
oxygen want there is very little increase of 
systolic or diastolic pressure as the heart rate 
increases. In the worst type the diastolic 
falls first, then the systolic, after which the 
pulse slows down. This results in the faint- 
ing of the person subjected to the test. The 
first type may "lose consciousness without 
fainting. He quickly recovers when re- 
stored to air, while the heart rate and blood 
pressures are soon back to their normal. The 
fainting type rarely endures so low an oxygen 
and if allowed to run his course faints com- 
pletely, and as he revives he requires an hour 
or two, to regain his normal pulse rate and 
blood pressures/' * 

*Op. cit. p. 179. 



OXYGEN AND EFFICIENCY 147 

Such facts as those coupled with the many 
experiences of mountain climbers and balloon- 
ists made it evident that some systematic 
study of the aviator's ability to withstand the 
effect of oxygen deprivation should be made. 
The English and the French both made some 
studies of the physiological effect of oxygen 
hunger, but the most thorough-going work was 
done in the American Medical Research Lab- 
oratory. The apparatus used was a metal 
tank containing air so connected with rubber 
piping that the air could be drawn from it by 
inhalations and the breathed air returned to 
it (with the C 2 eliminated) by exhalations. 
The rate and depth of breathing were also re- 
corded and the amount of oxygen remaining 
in the tank was determined after the test. The 
subject of the test sat with the rubber pipe 
comfortably arranged in his mouth and with a 
clip fastened to the nose to prevent air enter- 
ing the nasal passages. Before him was a 
table upon which were two rows of small elec- 
tric bulbs, with small brass screw-heads in two 



i 4 8 THE AVIATOR 

rows also, corresponding in alignment to the 
bulbs. When a bulb was lighted the subject 
reached forth with a stylus which he held in 
his right hand and touched the corresponding 
screw-head. A light appeared about every 
second in some one of the bulbs, he could not 
tell beforehand which. This kept him con- 
stantly on the watch. In addition to touch- 
ing the screw-heads, he had to keep watch 
upon an ammeter, whose dial was right before 
him. When the hand moved he moved it back 
to its original position by moving a slide, on 
which his hand rested when not engaged in 
reaching to the lights. Moreover, a small 
motor was kept running, which occasionally 
raced at high speed. When it did so it gave 
a shrill tone. The subject brought the motor 
back to the original tone by pressing his foot 
on a pedal beneath the table. 

These three reactions he was obliged to 
make at any moment during the test, and they 
were timed in such a way that he could 
take care of all three by sticking strictly to 



OXYGEN AND EFFICIENCY 149 

his task. As the lack of oxygen began to af- 
fect the man, the psychologist, who had charge 
of these reactions, could notice characteristic 
changes in the time and manner of reactions. 
These were considered as the results of some 
loss of ability in attention, or in motor co- 
ordination. Such faults as failing to notice 
a change in the ammeter, or not observing a 
light when it appeared, or ignoring a change 
in the tone of the motor were rated as atten- 
tion defects. Slow movements, too slow in 
reaching the targets, or fumbling, hesitancy 
and inaccuracy all were counted motor de- 
fects. 

The actions of the subject being tested were 
closely studied and a brief description was 
recorded for each minute of the test. It 
seemed that the average man showed some 
defect in both attention and motor control 
after about fifteen minutes of the test. Then 
he would frequently regain his abilities and 
proceed as before, striking his targets as each 
light appeared, correcting his ammeter, and 



150 THE AVIATOR 

motor, as he caught the signals. After some 
twenty-five or thirty minutes the oxygen in 
the tank would be in the neighborhood of 7 
per cent instead of the normal 21 per cent 
and a very frequent result would be a lapse of 
the attention and an ignoring of the sound 
of the motor. Usually there would be symp- 
tomatic evidences of loss of motor control be- 
fore this, such as too vigorous thrusts with the 
stylus and an awkward jerking of the ammeter 
slide. Whether it was attention, or control 
of movements, that gave the signal of the ap- 
proaching collapse it was usually the psychol- 
ogist who obtained the first information of 
the subject's inability to continue. 

Not infrequently the men watching the 
heart, the pulse and the blood pressure would 
call a stop to the test. In such cases the 
subject's vital organs were evidently unable 
to continue the strain. A sudden drop in the 
heart rate or the blood pressure would indicate 
the inability to keep up the fight. 

In addition to a study of the psychological 



OXYGEN AND EFFICIENCY; 151 

reactions and the vital functions, an eye spe- 
cialist studied the convergence of the eyes and 
their accommodation for near point. A study 
of thirty-five men showed a considerable loss 
of strength in the muscles of the eyes during 
the rebreather test. At the equivalent of 
heights of ten and fifteen thousand feet, men 
with slight convergence defects would "see 
double-" 

The value of these rebreather tests \vas 
considered so great that they were being in- 
stalled in the flying fields throughout the 
country when the Armistice was signed. Like 
other scientific efforts of the war emergency 
they leave much to be desired. Occasionally 
a man gives a different rating in several tests. 
Then one begins to wonder how much depend- 
ence can be placed on the tests. It may be 
due to changed physical condition of the man 
from time to time. If so, this should be 
known, and no man should be finally rated 
with but one test to his credit. Moreover, 
scientific practice would insist that the ratings 



152 THE AVIATOR 

of the men in the rebreather and the actual 
records of men in altitude flying should cor- 
relate. It rather shakes one's confidence in 
the rebreathing tests to find a man rated low 
who flew in France during the war and who 
goes to the equivalent of 18,000 feet in the 
low pressure chamber with no evidences of 
any deterioration in ability. Certainly the 
tests ought to pick out men who are organic- 
ally unable to resist oxygen want at any time 
and if they accomplish no more than that they 
have a practical value. 

An evolution of these and other tests will 
certainly occur, and it will eventually be prac- 
ticable to tell each candidate for aviation 
what his native abilities are in resisting oxygen 
want and what tricks his physique can 
play on him while he is under the strain. 
Indeed, the latter service may be the more im- 
portant after all. When you have found 
your senses reliable for twenty years or more, 
it is rather hard to doubt them when they be- 
gin playing tricks. Everyone should know 






OXYGEN AND EFFICIENCY 153 

what the tricks are in order that he may rec- 
ognize them if they should appear. But most 
important of all, everyone should get "the oxy- 
gen habit." It is the sure antidote for air 
troubles! No patent medicine eulogy can be 
half so true as a description of what oxygen 
does for the altitude troubles. It relieves that 
dizziness, and cures the faintness! It clears 
the vision and relieves the heart and the 
breathing ! It sobers the emotions and relaxes 
the strain! It cures that tired feeling! In 
short it is a panacea. Moreover, it is a nat- 
ural food and not a stimulant. Its cure is 
Nature's cure. Not only is it good for the 
trouble at the outset but it is excellent as a 
restorative after a flight when one feels worn 
out and suffers from that splitting headache. 
Surely what the flying machine loses in the 
added weight of an oxygen tank the flier more 
than gains in comfort and efficiency. To con- 
vince every flier that he should take his oxy- 
gen tank when he expects to go to ten thousand 
feet or more and to stay there any length of 



154 THE AVIATOR 

time, nothing could be better than to put him 
through the rebreather tests a few times. 
Then the value of oxygen would be so clear 
in his mind that no further arguments or dem- 
onstrations would be needed. The experien- 
ces of Major R. W. Schroeder constitute one 
of the best arguments possible for the use of 
oxygen in all altitude work. 1 He writes a de- 
scription of his experiences in seeking to make 
a record altitude flight which bears out the 
findings of the laboratory in a striking way. 
"I did not seem to be able to go above 
23,000 feet at any time without feeling a sort 
of sleepy, tired, cross and hungry feeling, 
which I was unable to overcome except by the 
use of oxygen. Without the use of oxygen 
at these altitudes, I would feel that I was 
doing everything just right, and even if the 
aeroplane would get into some critical position 
and I could see when I looked down that the 
earth that should be underneath me was not 
there any more, but was way over on the other 

1 Mental Hygiene, Vol. Ill, No. 2, pp. 297-299. Quoted 
from "Flying." 



OXYGEN AND EFFICIENCY 155 

side of the machine, yet I believed I was flying 
all right, and that my flying position was 
right, but the earth was in the wrong place. 
So after these experiences, I decided that I 
would have to overcome these dangers, and the 
way I did it was to keep my mind on one 
thing; and that was, when the earth was in 
the wrong place, use oxygen. This I did and 
found that it worked out very well. . . • The 
following experiences and sensations I no- 
ticed during my flight were due to lack of 
oxygen. I took off at 1 : 45 P. M v Wednesday 
September 18, 191 8, and made a steady circu- 
lar climb, passing through clouds at 8000 
feet, 12,000 feet and 16,000 feet. . . . When 
I reached 25,000 feet, I noticed the sun grow- 
ing very dim, I could hardly hear my motor 
run, and I felt very hungry. The trend of 
my thought was that it must be getting late, 
that evening must be coming on and that was 
the reason the sun was getting so dim. But I 
was still climbing, so thought I might as well 
stick to it a little longer, for I knew I could 



156 THE AVIATOR 

reach my ceiling pretty soon, then I would go 
down, and even though it were dark, I could 
land all right, for I had made night landings 
many times before ; and so I went on talking 
to myself, and this I thought was a good sign 
to begin taking oxygen, and I did. I was 
over 25,000 feet and the temperature was 60 
degrees centigrade, below zero. As soon as 
I started to inhale the oxygen, the sun grew 
bright again, my motor began to exhaust so 
loud that it seemed something must be wrong 
with it. I was no longer hungry and the day 
seemed to be a most beautiful one. I felt like 
singing with sheer joy as I gazed about 
through the small portions of my goggles, 
which had no frost, due to a drop of oil which 
had splashed on them from the motor. . . . 
When I was about 27,000 feet, I had to re- 
move my goggles, as I was unable to keep a 
steady climb. My hands by this time were 
numb and worried me considerably. The 
cold raw air made my eyes water and I was 
compelled to ride with my head well down 




OXYGEN AND EFFICIENCY 157 

inside the cockpit. I kept at it until my oxy- 
gen gave out, and at that point I noticed my 
aneroid indicated very nearly 29,000 feet. . . . 
The lack of oxygen was affecting me and I 
was beginning to get cross, and I could not 
understand why I was only 29,000 feet after 
climbing for so long a time. I remember 
the horizon seemed to be very much out of 
place, but I felt that I was flying correctly, and 
that I was right and the horizon was wrong. 
About this time the motor quit, I was out of 
gasoline, the propeller stopped and every- 
thing was quiet, so I went down in a spiral. 
When I had descended to about 20,000 feet 
I began to feel much better, and realized that 
the lack of oxygen had affected me. ... I 
noticed that as I descended the air seemed to 
be thick and stuffy, but very nice and warm." 
The effect of the rarified air upon the avia- 
tor is illustrated by this adventure in a very 
interesting way. It must not be imagined, 
however, that it is necessary to rise to any 
such great altitude to duplicate these expe- 



158 THE AVIATOR 

riences. At much lower altitudes the same 
sort of emotional changes, bizarre ideas, and 
blurring of vision and hearing occur. All 
that is necessary for these effects is a dimin- 
ished supply of oxygen. Often the emotional 
effects will be felt after long flying at much 
lower altitudes. 

It is a wise aviator who knows when his 
feelings are playing tricks on him. A very 
observant Canadian flier, who did a great deal 
of scout duty in France, stated that his feel- 
ings were unpredictable. On some days, 
when flying between fifteen and twenty thou- 
sand feet, life would become intolerable. 
There might be no obvious dangers, but the 
whole aspect of life itself would become so 
abominable that he would actually contem- 
plate crashing his ship and ending the whole 
miserable business. On other days the air 
seemed to be the only place in the universe 
worth while. On such a day very distress- 
ing things could happen without affecting his 
complacency at all. A comrade's ship might 



OXYGEN AND EFFICIENCY 159 

suddenly be missing without causing him any 
worry, or concern. He knew his emotions 
were not functioning in a normal way. He 
attributed the condition to diet and the abnor- 
mal environment of the war. Undoubtedly 
both of these had their influence, but the thin 
air was the real, underlying cause. 

The early experimenters with the "re- 
breather" tests noticed these emotional changes 
in their first tests for the effect of diminished 
oxygen. 

In a series of experiments to determine the 
effect of altitude upon the quickness and ac- 
curacy, with which the aviator moved his con- 
trols, I found these emotional experiences very 
common. * The apparatus used was a large 
steel chamber from which the air was pumped 
in such a way that an equivalent in air pres- 
sure for any altitude up to twenty thousand 
feet was easily obtained. The man being 
tested would jot down notes at different "alti- 
tudes." 

1 McComas, H. C, "Controlling the Airplane at Twenty 
Thousand Feet." Scientific Monthly, Jan., 1921. 



i6o THE AVIATOR 

A facsimile of some of these notes is given 
on page 160. The man wrote the first note 



*\ttX vr»*\ fo«* - Q^kJ^ Jl^J^^f 

Notes Made at the 20,000 Feet Altitude 
The first line is in the writer's normal handwriting. 

after he had been making his reactions at the 
equivalent of twenty thousand feet for ten min- 



OXYGEN AND EFFICIENCY 161 

utes. He had # been in the chamber for a half 
an hour before this "altitude" was reached, as 
the air was gradually rarified. His hand- 
writing in the first note is nearly normal. 
Later it becomes almost illegible. The blur- 
ring of vision mentioned is often noticed. In 
my own case the light within the chamber 
became so dim that I thought several of the 
electric lights had burned out. Some of this 
blurring is due to lack of eye balance, but the 
most noticeable feature is a dimming of vision. 
Notice that this first note mentions an un- 
concern about the character of the work being 
done. That was not the normal attitude of 
the man, who was most conscientious about 
his work. 

Ten minutes later he noted drowsiness, but 
was still in a high good humor. This note 
was also made at the twenty thousand feet 
"altitude." 

After another ten minutes at the same "alti- 
tude," during which he was reacting with the 
stick and rudder, his drowsiness had increased. 



1 62 THE AVIATOR 

His handwriting tells the story. By fighting 
off the lethargy he could continue to make his 
reactions, and they were as good as those he 
had been making at this "altitude" before. 

The fourth note was entered as the air pres- 
sure was being returned to normal, though it 
was approximately the same as that for twenty 
thousand feet. The reference to the attention 
is very interesting. Several men were im- 
pressed by the effect the low air pressure had 
upon the ability to keep the attention upon 
several things at the same time. This, of 
course, was very evident in the "rebreather" 
tests. The "span" of attention seems to be 
narrowed as one succumbs to the effects of 
altitude. 

The last note was made when the pressure 
was about the equivalent of that for fourteen 
thousand feet. The old complacency was 
gone. He had become irritable. This frame 
of mind contrasted sharply with the exhilara- 
tion he had been enjoying. The fact that he 
was "distractable" was in contrast with the 



OXYGEN AND EFFICIENCY 163 

previous condition. As the "span" of atten- 
tion comes back to normal, one becomes aware 
of a number of things of which he had been 
unconscious. These tend to distract his at- 
tention. 

The quickness and the correctness with 
which the men responded to the signals in 
moving their controls did not appear to be 
very much affected by the low air pressure, 
after they had reduced their responses to a 
habit. While they were learning to respond 
to the signals, the effect of the deprivation of 
oxygen was more evident. However, the pre- 
cision with which they moved the stick and 
rudder was often badly affected. Occasion- 
ally, they would throw their controls with a 
vigor that would have been disastrous in an 
airplane. 

The loss of oxygen robs the brain and nerv- 
ous system of its food. The result is apparent 
in the movements, and in processes of con- 
sciousness as well. If the effects were simply 
upon the movements of the limbs and did not 



1 64 THE AVIATOR 

reach the mind, the danger would not be so 
great, for the aviator would be aware of his 
deficiencies, but Nature plays a deceptive 
part, when the brain is robbed of oxygen. In- 
stead of the usual signals of distress, to which 
we are all accustomed when anything goes 
wrong with our physical machinery, there 
may be no signal at all, or there may be a false 
signal. The high flier may be tricked into be- 
lieving he is in extraordinarily fine condition 
while he is actually in a most abnormal state. 
Nature cannot be trusted in this matter. She 
may become a siren luring the air navigator 
into dangers far more terrible than the fabled 
rocks. 



CHAPTER IX 
DOING STUNTS 

WORDS are sometimes best understood by 
means of their pedigrees. The word "stunt" 
would seem rather common, perhaps a little 
vulgar, but in reality it comes of very good 
stock. It undoubtedly came over in the May- 
flower, and can trace its lineage back to Wil- 
liam the Conqueror. It originally meant a 
task, a piece of work ; not the sort of thing one 
does when he is "stunned," nor the sort of 
thing one does to "stun," or astonish, some one 
else. With the original meaning in mind, 
consider the stunts of the aviator. 

Two things impress us immediately, in con- 
nection with tricks in the air: first the strain 
on the machine and its adaptation for the 
work; secondly, the same in connection with 
the man. Machines may be braced to stand 

165 



1 66 THE AVIATOR 

the strain. There are also certain types which 
are much better constructed for trick work 
than others- What about the man? He, too, 
needs some bracing in a sense to be explained 
later, and he certainly must be of a type 
adapted to the work. 

During the war, the machines made and 
the sort of flying done were all designed to 
meet certain needs, which are quite different 
from those in times of peace. Fast planes 
were demanded — not safe ones. Aircraft that 
would climb steeply and manoeuvre quickly 
were the necessity. Quite different in pur- 
pose and construction are the commercial air- 
planes. In them safety and reliability are in- 
dispensable. In dodging the "archies" and 
in escaping pursuing crafts, all sorts of ma- 
noeuvres were evolved which have no value 
in peace times. Indeed, the value of the very 
tricks developed for war service has been ques- 
tioned. An inexperienced pilot who did his 
manoeuvring awkwardly fooled the anti-air- 
craft gunners more than the skilled flier who 



DOING STUNTS 167 

flew according to the rules of the tricks! No 
one could tell what direction the novice doing 
a "falling leaf" performance was going to 
take. He could not tell himself. It was im- 
possible to anticipate his position and aim 
ahead of him. For this reason many a fool 
rushed in where angels would fear to fly; and 
rushed out again, none the worse and none the 
wiser. 

About the best that can be said for the art 
of stunting is that the man who has learned 
the knack of putting his ship into all sorts of 
unusual positions and pulling her out again 
acquires an invaluable control over his craft 
and gains an invaluable confidence in himself. 
If these acquisitions were the real motives for 
stunt practicing, no complaints would be en- 
tered against it. But when a man imperils 
his craft and his life merely to surprise some 
spectators, it is hard to condone his perform- 
ance no matter how clever, or successful, it has 
been. In no case is stunting near the ground, 
which gives rise to so many accidents, permis- 



1 68 THE AVIATOR 

sible — among sane people. The real value 
lies in trying out a ship at such altitudes that 
the mind can be given to the technique of 
the work without a thought of the ground. 
Such a tryout is a distinct advantage. One 
comes to know just what is the stalling angle 
of his machine. He finds out how she tends 
to fall when stalled and he learns to regain 
his speed and bring her again to a level. He 
learns to do a steep bank and to accustom him- 
self to the changed relation of the wheel and 
rudder when the machine is in a vertical 
plane. Such knowledge is always serviceable. 
Moreover, it is very well to become accus- 
tomed to unusual positions and motions. Be- 
fore Houck undertook the "loop" he prac- 
ticed inverting himself near the ground. It 
may not have been dignified but it gave him 
the experience he needed. When an air- 
plane develops engine trouble, or trouble with 
the controls, the pilot may find himself sud- 
denly in an unusual position, which may con- 



DOING STUNTS 169 

fuse him badly. Here his experience in stunt- 
ing is a most invaluable asset. 

An illustration of this asset occurred while 
a cadet was flying in a Southern field. It 
seems that trouble developed in his elevators. 
He believed it due to a tail slide. It was pos- 
sible to steer down but not up. He dove 
toward the ground, then he threw the stick 
forward and shut off his engine. This made 
the craft fly upside down some fifty feet above 
the ground. Of course that is no position for 
a comfortable landing. When the ship began 
to lose headway he threw the stick to one side 
bringing the craft to a vertical position so that 
a wing hit the ground first. It was a "crash," 
of course, but the pilot escaped with his life. 
This he never could have done without prac- 
tice in stunting. 

From the discussions in the preceding chap- 
ters there are certain deductions which must 
be made concerning trick flying. McMinnies 
makes the first feat in advanced flying an 



170 THE AVIATOR 

ascent to 10,000 feet 1 He warns the aviator 
against coming directly to the ground after 
flying at such a height. It is wise to circle 
above the landing ground at a height of 1000 
feet "so as to accustom himself to the appear- 
ance of the ground at this height" Not only 
does the ground look different but if the avi- 
ator has any muscular unbalance of the eye 
muscles, the strain of flying and the depriva- 
tion of oxygen even in altitudes around 10,000 
feet will give him a diplopia. That is, the 
eyes will not converge as they should and there 
will be double images and blurring of vi- 
sion — just the sort of trouble which makes for 
a bad landing. Then, too, the strain of trick 
flying at heights means a high consumption of 
oxygen and though he may not realize it, his 
coordination in movements may be consider- 
ably below his average. Nothing can be lost 
by a circle or two before a final glide to the 
field. 
What was said concerning the vertigo and 

1 McMinnies, W. A., Practical Flying, p. 186. 



DOING STUNTS 171 

nystagmus in a preceding chapter has pecu- 
liar cogency in stunt flying. There is a diz- 
ziness due to the lack of oxygen supply in the 
brain at high altitudes. Such a type of diz- 
ziness might well be augmented from quick 
turning movements. An excellent practice is 
to try out the stunts in an orientator first. 
The movements are not exactly the same, of 
course, and the orientator may be much more 
sensitive to its controls than the ship. But 
the knack of manipulating the controls in 
every imaginable position can be acquired and 
the tolerance of vertigo can certainly be ac- 
quired. If continual practice in stunting in 
the air is impracticable, the orientator should 
be used to keep oneself in condition; for the 
control one acquires from stunting is like 
"sailors' legs," after a few weeks on shore you 
lose the knack of walking on the rolling deck, 
and the physiological adaptation against sea- 
sickness. It is out of keeping with all expe- 
rience to expect to go into the air, after a va- 
cation, and do the stunts which came easy 



172 THE AVIATOR 

when one was in perfect practice; as it re- 
quires some time to acquire the art and to 
overcome the vertigo. 

In line with this principle is the need of 
getting again the "feel of the ship" before 
stunting. Some men cannot do a simple turn 
without getting dizzy, when they have been 
out of an airplane for two weeks. What 
would happen if they chanced into a tail spin 
can easily be imagined. It is a nice test of 
one's "feel" to do "tight eights." Why not 
try that at an altitude of 2500 feet before at- 
tempting to satisfy oneself that he has lost 
nothing from •his lack of practice? If the 
average aviator could bring himself to see 
that it is no reflection upon his character, or 
courage, to lose the feel of the ship and to be 
obliged to start slowly in regaining his art, it 
would be a most excellent thing for him and 
for his ship. 

Probably this very trait of careless daring 
is the young aviator's best asset, as well as his 
greatest liability. Certainly, older men do 



DOING STUNTS 173 

not acquire the ability to stunt as do the 
younger. This cannot be due to any com- 
plexity in the tricks. Most of them call for 
rather simple movements. It seems to go 
back to something inherent in maturity. 
Perhaps the average man of forty who has 
kept himself in good physical condition does 
not realize the habits of caution he has been 
building all these years. Where he gladly 
took chances in his youth, he avoids them now. 
A slippery pavement no longer entices him, 
he walks around it. He does not find the 
temptation to skate across a strip of thin ice 
irresistible and he feels no craving to walk 
across railroad trestles. Why? The ques- 
tion seems foolish — to the citizen of forty. 
At eighteen the quiver of excitement that such 
escapades induced was one of the most enjoy- 
able that he knew. Now, there is no demand 
for this type of pleasure and habits of caution 
take its place. 

When the middle-aged man steps into an 
airplane he may have all the self-control of 



174 TH E AVIATOR 

youth, and all the courage, too; but in the 
face of a sudden impending danger the habit 
of self-protection is not to be denied. The 
training of his mind which makes for caution 
will assert itself. He cannot depend upon 
himself to seek out the dangerous and throw 
himself into it. 

A sage instructor told a man of forty that 
he might do straight flying and only straight 
flying. Beyond that he could not go, as the 
"dead line of forty" in this case is straight! It 
has no loops, or rolls. 

Occasionally the youth of twenty lacks the 
temperament for stunting. In terms of phy- 
sique rather than courage, he is so built that 
the imminence of danger gives rise to an ex- 
cess of the internal secretions and these make 
for strong vigorous movements rather than 
small controlled ones. As a result he cannot 
make the nice reactions required for trick fly- 
ing. He is "nervous" and cannot keep 
"cool." 

Altogether, it is a rather select grade of 



DOING STUNTS 175 

human being that qualifies as a stunt flier. 
Nature must endow him with good vital or- 
gans to stand the strain of high flying and 
continuous flying. His senses must be per- 
fect No eye defects, no ear, or balance- 
sense imperfections can be present. The 
senses of touch and movement must be finely 
developed. There must be quick reactions 
and decisions. No mental sluggishness can be 
tolerated. Last, and by no means least, grant- 
ing all of these native endowments, he cannot 
permit himself to get out of condition. As 
the athlete is compelled to keep in form for his 
work, the aviator is forced to keep in training 
for his. Aviation is an exacting mistress. 
She will have only the best at their best. 



CHAPTER X 
SELECTING THE AVIATOR 

The widest differences of opinion have ex- 
isted concerning the methods of selecting men 
for aviation. On the one hand, the sort of 
man who would make good in the air was con- 
sidered a type which was useless in everything 
else. This is the idea underlying the facetious 
remark, "He ought to be good in the air for 
he is no good on earth." On the other hand, 
the flier has been deemed the finest type of 
man from every point of view. 

During the war, when it was necessary to 
select thousands of men for aerial work, a 
common ground between these two contrasting 
opinions was found. At first there was no 
definite way of selecting fliers; but, as time 
went on, it became apparent that the haphaz- 
ard choices were not always fortunate. Grad- 

176 




SELECTING THE AVIATOR 177 

ually some systematic methods were evolved 
for picking the men. These were concerned, 
at first, with the physique simply, then, the 
man as a personality became a feature of the 
examination. Finally, the special traits which 
were considered necessary for the aviator 
were made the subjects of scientific study. 

Before we entered the war the European 
nations in the conflict had each developed an 
air service and by the time of our entrance they 
were in the position to give us very material 
aid in selecting and training our aviators. 
From the Germans there was not much infor- 
mation forthcoming. It was known that 
they had a systematic way of watching their 
aviators and of calling a man out of the work 
for a rest when he gave evidence of staleness. 
It seems that they selected their men largely 
from the cavalry with a view to getting men 
of a certain type. 

The French undoubtedly would have been 
much more exacting in their requirements for 
the aviator if they had had a great supply of 



178 THE AVIATOR 

young men from whom they might make their 
selections, as we had. As it was, they could 
not afford to make their restrictions too rigid. 
A very good resume of their requirements is 
as follows: 

(i) A normal visual acuity for the two 
eyes and for each eye, any corrections by 
glasses, not being permitted. 1 

(2) A normal binocular field, the abil- 
ity to distinguish clearly between green 
and red and to recognize the principal 
colors. 

(3) A normal auditory acuity, and a 
healthy condition in the middle and inner 
ear and in particular the organs of equi- 
libration. 

(4) An absolutely healthy condition of 
the organs of respiration and circulation. 

(5) A maximum weight of 85 kilograms 
(187 lbs.) for the student pilots and 75 
kilograms (165 lbs.) for the student ob- 
servers, bombers, and gunners, the weight 

1 Galtier M., Le Pilotage des Aeroplanes p. 6. 





SELECTING THE AVIATOR 179 

being taken when in uniform, but without 

arms or equipment. 

These requirements are not considered very 
severe and the administration could accept 
an exceptionally promising man even though 
he has not fulfilled all of them. As an in- 
dication of a man's general ability for avia- 
tion, he was expected to describe any heredi- 
tary defects and any personal nervous defects. 
Also, he should indicate whether he had qual- 
ified in the service or disqualified by any ill- 
ness or wounds. 

In short any military man qualified or not, 
even though he may have only a simple pri- 
mary instruction can become a perfect pilot 

"It is sufficient to have average health, the 
right spirit and above all to know how to 
think." (Savoir reflechir) . 

Surely that is not a very difficult program 
for the candidate in aviation to meet. 

The French were developing their scien- 
tific study of the flier when the war ended. 
They were doing some work upon the effects 



ii 8o THE AVIATOR 

of oxygen want, upon the internal ear and 
upon reactions. The necessity for such re- 
search and for more thoroughly scientific ex- 
aminations of their airmen was undoubtedly 
becoming more generally recognized. 

Some of their work aroused much interest 
in this country. It was designed to detect 
nervous instability, by measuring a man's rate 
of breathing and pulse and the steadiness of 
his hand under normal conditions. While the 
measurements were being taken by means of 
recording apparatus a sudden noise, an ex- 
plosion or pistol shot occurred behind the 
candidate. Naturally, his heart and breath- 
ing rates would change and there would be 
involuntary movements of the hand. The 
amount of change was recorded and those 
whose rates changed least and whose jerk of 
the hand was smallest were considered the 
better type of pilot. Some figures comparing 
these reactions for several fighting pilots 
seemed to indicate that the men who were 
most successful as aerial fighters were the 



SELECTING THE AVIATOR 181 

least affected by the sudden disturbance. 
American psychologists, as a rule, did not 
feel that very much reliance could be placed 
upon this type of test for the reason that the 
reactions due to genuine emotions are noto- 
riously hard to get in experiments. Never- 
theless, such investigation is along the right 
lines and will prove valuable, if the experi- 
mental conditions can be brought to simulate 
the actual. 

The French did some interesting work upon 
reaction time as a means of detecting a can- 
didate's native quickness of response. This 
is a very familiar test. A signal is given, 
such as a light flashed, or a bell struck, and 
the candidate presses a key the instant he sees, 
or hears, the signal. The time is taken be- 
tween the stimulus and the reaction by caus- 
ing a specially made clock to start running 
simultaneously with the signal and to stop 
with the reaction. These clocks register 
time in one thousandths of a second. The 
average time of a visual reaction is about .195 



ii 82 THE AVIATOR 

of a second and of an auditory reaction about 
.145 of a second. Men whose average re- 
actions were conspicuously longer than these 
averages, would be considered too slow to 
become successful fighting pilots. 

Among the American scientists the prevail- 
ing belief was that the reaction time did not 
tell as much about the aviators quickness 
and accuracy of movements as discrimination 
time. In the latter it is necessary not only 
to react but also to think and to decide what 
reaction to make. 

The Italians were very insistent upon the 
use of reaction time tests and disqualified a 
number of candidates who were slow reactors. 
They also used the "surprise" tests for de- 
tecting increase in pulse and heart rates. 
They did not put much stress on the effect of 
oxygen want, nor select aviators on the basis 
of their resistance to it. 

England did not begin a systematic effort 
to select her aviators scientifically until late 
in the year 1916, when a special medical board 



SELECTING THE AVIATOR 183 

was formed in the Royal Flying Corps to 
select men for the service and to pass upon 
men whose fitness for their work was ques- 
tionable. This board did such valuable work 
that it was enlarged and was brought into 
relation with the Medical Research Com- 
mittee, later it was known as the Air Force 
Medical Service. 

Surgeon-Lieutenant Anderson has described 
their methods of selecting aviators, and inas- 
much as our own methods were in part 
based on the English it is not necessary to pre- 
sent them in detail. 1 There was a thorough- 
going examination of all candidates for fly- 
ing officers and the medical history of such 
officers was kept by the physicians attached 
to the Royal Flying Corps. Experiments 
were made to find which men were best 
adapted to different kinds of aerial work, 
with special emphasis upon work at high al- 
titudes. 



1 Medical and Surgical Aspects of Aviation, H. A. Anderson 
pp. 18-40. 



1 84 THE AVIATOR 

When we went into the war, it was at once 
apparent that we could easily find all the 
young men we needed for the Air Service and 
that we could well afford to select the most 
efficient. The Aviation Examining Board in 
Washington was expanded until in January, 
1 91 8, there were 67 examining units in dif- 
ferent parts of the country. These units used 
the same tests and the same methods. The 
famous examination blank "Form 609" was 
filled in by examiners of youths from San 
Francisco to Boston. This principle was al- 
ways in mind, that the examinations should 
be standard, permitting no exceptions which 

might make them easier in one place than 
another. 

This examination consisted of very 
thorough examinations of the eyes, ears, throat 
and nose. The sense of balance was tested 
by the rotation tests and by observations of 
the candidate as he stood, or walked, with 
eyes closed, A general physical examina- 
tion followed for the gross structure and the 



SELECTING THE AVIATOR 185 

vital organs. An estimate of the candidate's 
nervous system was obtained from some of 
the examinations of the eyes and ears and 
from a few tests for reflexes and coordination 
in movements. 

These tests separated the obviously impos- 
sible candidates from those who could go on 
into the ground schools and flying schools. 
Later they were, in many cases, tested for 
their ability to withstand oxygen want. 

The flight surgeons were a further means 
of selecting efficient fliers. They became in- 
timate with the young aviators and were in 
a very fortunate position to observe the traits 
which the promising men showed. Such 
observations by scientific men will prove of 
very great value when these surgeons finally 
pool their findings. Information of this char- 
acter will be the real basis for future progress 
in selecting men for the Air Service. As an 
example of the way some of the flight surgeons 
went about this unusual and difficult work of 
caring for the men on flying duty and of eval- 



1 86 THE AVIATOR 

uating them, mention should be made of the 
notes taken which shrewdly classify the young 
fliers on the basis of their civilian occupations, 
their athletic achievements, their mental alert- 
ness and temperamental traits. One flight 
surgeon studied the movements of his men 
not only in their work, but when they were 
off guard and acting naturally. He noticed 
the quickness and precision with which they 
did habitual things, such as lacing their boots, 
or dressing. He was on the lookout for the 
way in which they picked up habits and how 
consistent they were in their habits, even in 
such simple things as the way in which they 
formed their letters in writing. His analysis 
of his men went into everything he could ob- 
serve. There were no "snap judgments" of 
his men, he knew what he thought of them 
and why. Naturally his position on the fly- 
ing field became more and more important. 
His estimate of what the cadets could do, and 
when a man was becoming unfit to fly, won the 
respect of the flying officers. Nothing could 



SELECTING THE AVIATOR 187 

better supplement the examinations of men 
for aviation than the judgment of men of this 
type. 

Had the war lasted a year longer, the re- 
search work in this country and abroad would 
have made the selection of the type of man 
who can become an accomplished flier a mat- 
ter of scientific accuracy. Various investi- 
gations were in progress attacking the prob- 
lem from a number of different angles. Some 
practical results were obtained and were being 
used as a means of selecting aviators, making 
use of tests for stability of hand, perception 
of change in position, variations in respira- 
tion, mental alertness and athletic ability. 1 

x Air Service Tests of Aptitude for Flying," Journal of Ap- 
plied Psychology, 1919, Vol. Ill, pp. 103-109. 

See also Ddtekeray and Isaacs. "Psychological Research in 
Aviation." Comparative Psychology Vol. I No. 2, pp. 11 5-148. 



CHAPTER XI 

TYPES OF AIRMEN 

No TWO persons are exactly alike. Bertil- 
lion took advantage of this fact to identify any 
one person among the millions of his fellows. 
Slight differences in the measurements of the 
length and breadth of the head, the lengths of 
the forearms, middle finger and foot, serve as 
indices of the individual. Naturally, the dif- 
ferences in the nervous systems among men 
must be even more striking. We are pre- 
pared, then, to learn that there are large dif- 
ferences in the time it requires to feel a sen- 
sation and to make a hand move. The 
French and Italian air services, as we have 
seen, sought to use these tests for quickness 
in selecting their aviators. Other more com- 
plex activities of the nervous system show 

more conspicuous differences. 

188 



TYPES OF AIRMEN 189 

The question naturally arose, what traits 
does the airman possess which distinguish him 
from his fellows? Is he a type? To this 
question the answer was an emphatic "yes," 
before we raised our army of aviators. Now 
there is somewhat less certainty. Among the 
thousands of young men who have won their 
wings, there is such a wide diversity that some 
flying officers have told me they do not believe 
there is any one type peculiarly adapted to 
the work. 

If that were so, we should be facing a most 
anomalous situation. It cannot be so, as a 
moment's reflection will show. This army 
of all sorts of young fliers is, after all, a se- 
lected one. The type of men entering the 
ground schools was selected. They were ex- 
ceptionally intelligent and in many cases were 
highly educated. The ground schools elim- 
inated many, and the flying schools selected 
from the graduates of the ground schools. 
They do not seem a superior type for the 
simple fact that our country is peculiarly for- 



i 9 o THE AVIATOR 

tunate in having so many of them. Never- 
theless, they are a type. This is evident, first, 
from their physical examinations, whidh 
were more exacting than any others ; and, sec- 
ondly, from their ability to learn both a science 
and an art. They were the type that Cecil 
Rhodes sought, when he established his 
scholarships. The type which every Anglo- 
Saxon admires. 

Though the flying officers did not profess 
to detect a distinguishing characteristic for 
the large group which made fliers, it was sel- 
dom that they did not express confidence in 
their ability to distinguish types of aviators 
among the fliers themselves. To do this suc- 
cessfully they would rate the pupils according 
to the way they learned their flying. Each 
day, whether the student flew alone, or with 
his instructor, a record was kept of his devel- 
opment. It noted more than the pupil's prog- 
ress in flying; it recorded facts that described 
the personality of the man, his alertness, in- 
telligence, persistence and any trait the in- 



TYPES OF AIRMEN 191 

structor might notice. One thoughtful 
teacher timed a pupil as the latter put on his 
goggles and strapped himself in the seat. It 
required eleven minutes! And this man had 
been an "honor man" in the ground school. 
He never learned to fly. Many little traits 
and habits take on new significance in aviation. 
Not the least of these is decision. This same 
instructor would shut the throttle off at un- 
expected moments and "size up" his pupil 
by what reactions were made quickly and cor- 
rectly. From such observations the pupils 
were rated, as well as from the records in the 
routine work. The result gave a final rating. 
In the land schools there were three types of 
fliers. The highest was the pursuit pilot. 
The "best" type of cadet was recommended 
for this work. Less efficient men were recom- 
mended as bombers and the least efficient were 
considered fit for the observation and direction 
of troop movements! 

Surely this is a rough division of types. It 
is based on the kind of work the cadet did 



192 THE AVIATOR 

as a flier and the sort of personality he seemed 
to have. Of course, the pursuit pilot was the 
desired and admired career. His spectacular 
performances appealed to the average man 
most effectively. To succeed in this kind of 
work one needed to have a high rating on the 
"rebreather" test; because much of the scout 
work was done at great heights. He needed 
an excellent aptitude in flying. These two 
capacities could be determined easily, but 
a more subtle one is the willingness to fight. 
The Italians had some wonderful fliers, who 
would cut circles around telegraph wires, but 
who would not fight! Only as you know a 
man personally can you decide upon his will- 
ingness to fight Some general traits which 
a good fighter ought to have were observed 
and noted in the psychiatrical examinations. 
For example, the type of man who is neither 
fidgety, nor phlegmatic, but who carries him- 
self easily in normal life, has a natural ad- 
vantage as a fighter. He would be more apt 
to find it easy to exercise judgment and ma- 



TYPES OF AIRMEN 193 

noeuvre for a position, when he sighted a hos- 
tile plane, than the more highly strung man, 
who can hardly keep in one position for five 
minutes at a time. Of course, the chronic op- 
timist, the man who never worries and is con- 
fident in himself has a big lead over the less 
confident and more hesitant fighter. But 
there does not seem to be any rule we can fol- 
low. Some men fight in. one way, some in 
another, fighting courage is common to them 
all ; and the best test of it is the fight itself. 

The bomber was commonly supposed to be 
something less of a "live wire" than the pur- 
suit pilot. Cadets who did not excel in the 
stunting, but who had level heads and did 
reliable work, were considered of the bomber 
type. Such a one was not supposed to re- 
quire the quick reactions, or to use such in- 
itiative and ingenuity as the scout, As a 
sample of the bomber's life we may take the 
statement of a man who served in France for 
several months in this capacity. The work, 
he said, lacked zest. One was given so many 



i 9 4 THE AVIATOR 

"eggs to lay" and he flew to certain objectives 
and dropped the bombs upon them if possible. 
It becomes monotonous. My informant re- 
marked it was not always easy to place the 
bombs, that he had missed a depot and hit a 
hospital three hundred feet away, on one oc- 
casion. In fact the finesse of the bomber's 
art is in estimating height, wind, direction 
and speed. Occasionally, a squadron of 
bombers was attacked. If it was but one en- 
terprising Boche they kept on, indifferent. 
They let him fire all his ammunition and go 
home. If larger numbers appeared there was 
a fight, or a flight. The bomber did not go 
out to fight. His duty was to destroy certain 
objects and go back to his lines. Certainly, 
this calls for a different make of man from 
the fighting pilot! 

The observer who signalled the movements 
of the men in the field, or who watched the fire 
of the artillery, may not have required the 
dash of the scout, or the calm of the bomber. 
He may not have been as good a flier as either, 



TYPES OF AIRMEN 195 

and he may have deserved the rating the fly- 
ing schools gave him, below that of his fellows. 
But he surely needed brains ! If any man was 
placed in this group because of deficiencies in 
general intelligence that was a crime! What- 
ever other traits he lacked, good judgment was 
indispensableo An illustration will be all 
that is needed to carry conviction upon this 
point. An army corps observer made one 
error. He threw a barrage upon his own 
men! One error, and he never flew again. 
The man who tells the incident declares this 
observer went insane. A poorer type of flier, 
perhaps, the signaller may be, but he must be 
a superior type of soldier. To see intelli- 
gently, when shells burst around the ship, and 
to analyze the situation and wireless direc- 
tions, with bullets occasionally puncturing the 
wings, calls for a control of one's faculties 
second to none! 

These were the three types as the flying 
schools conceived them. Of course the hydro- 
plane called for a different kind of work. 



196 THE AVIATOR 

This machine will not permit the manoeuvres 
possible to the airplane. The heavy floats 
render it impossible to do the stunts which an 
average training airplane is built to do. 
Many of the machines used by the navy are 
so large that it is quite practicable to fly 
them by instruments rather than by the sensi- 
bilities and the "feel of the ship," which the 
land pilot seeks to acquire. 

It is a significant and laudable fact that 
the navy-trained men made the first voy- 
age across the Atlantic, and won their success 
by scientific planning and practices. They 
pointed the way for the future development 
of aeronautics. In times of peace, the scien- 
tific type of aviator will undoubtedly sup- 
plant the spectacular type. 



CHAPTER XII 
THE PILOT AS A PERSONALITY 

One of the questions which the practical 
flier used to ask the medical men who were en- 
gaged in testing aviators was this: "Well, 
what about Guynemer?" That appears to be 
an innocent sort of question, but it has very 
wide implications. Guynemer was the 
French ace who had the record for bringing 
down the greatest number of enemy planes; 
he also had the reputation of being physically 
inferior to many of his fellow aviators. In- 
deed, the French aviation schools would have 
rejected him on the basis of physical inability 
had he not succeeded by persistence and good 
fortune in winning a combat and in thus dem- 
onstrating his fitness as a fighting pilot. 
Perhaps his remarkable success accounts for 
the attitude of the French toward the tests 

197 



i 9 8 THE AVIATOR 

they used for admission to aviation and the 
insistence they had upon the right spirit, 
"l'esprit droit." As we have seen the re- 
quirements were waived by le Mvnistre in cer- 
tain cases, if the candidate promised well as a 
practical flier. 

This question put in a striking way the con- 
trast between the attitude of the examiner, 
who was taking stock of the aviator's different 
physical traits, and the instructor in flying, 
who was dealing with his pupils as men. It 
rather implies that an aviator in war work 
might be quite deficient in some of the ex- 
aminer's requirements and despite his defi- 
ciencies make an excellent combat pilot. In 
fact, a number of instructors insisted that the 
one criterion upon which they could base their 

opinions of a candidate was his personality. 
By that they meant the impression they ob- 
tained from working with the pupil. Im- 
pressions derived from observing a student's 
bearings, his comments on the work, his way 
of going about the tasks assigned him, all 



PILOT AS A PERSONALITY 199 

served as a basis for an estimate of his per- 
sonality, and this estimate the instructor felt 
was dependable. In many cases a caref-ul 
diary was kept by the flying officer in which 
he noted his student's attitude toward the 
work, whether he was cheerful and good-na- 
tured, kept at the work, learned easily, ac- 
cepted suggestions readily, or whether he 
failed in these and other traits. Such items 
added to observations upon the actual tech- 
nique of flying gave a pretty good description 
of the student's possibilities. Of course no 
practical flier would deny the value of tests 
for vision, hearing or accuracy of movements; 
nor, indeed, any test which involved the func- 
tions actually apparent in the work of control- 
ling a plane. iBut they were convinced that 
above and beyond any one group of capacities 
was the man's personality. A man, who was 
characteristically accurate in his every-day 
work, was apt to be accurate in .his flying, he 
would make good, "three point" landings and 
would not fly with one wing down, nor neglect 



200 THE AVIATOR 

his course. The alert student who was good 
at picking up new sports and games was often 
quick in picking up the tricks in flying. 
Good-natured, steady men remained so in the 
air. In general, the sort of personality you 
had on earth you had in the sky, — so reasoned 
the instructor, and he was largely right. 

Personality will assert itself in everything 
a man does. Given the same training and the 
same task to do, different men will do differ- 
ent kinds of work according to temperament 
and character. Naturally this is true in fly- 
ing as in anything else. 

What then is meant by personality? Or- 
dinarily we entertain very vague ideas about 
it. Often it serves as a convenient word to 
cloak an indefinite idea. We speak of the 
personality of a musician in interpreting 
music, or of an actor in presenting his role, 
because we cannot indicate clearly the fea- 
tures which distinguish the work. We real- 
ize that it is unique and peculiar to a partic- 
ular artist and the word "personality" is a 




PILOT AS A PERSONALITY 201 

useful means of escaping a clear analysis. 
The same vagueness characterizes our prac- 
tical conceptions of personality. Some people 
impress us in one way, some in another. Dif- 
ferences in bearing, voice, gestures, clothing, 
topics of conversation and numerous other 
particulars go into the making of certain types 
of personalities as we understand them. Fre- 
quently, our habitual way of "sizing a man 
up" is successful and the first impressions are 
verified by later acquaintance. We use a 
crude practical method of classifying new ac- 
quaintances, according to the features which 
happen to impress us. And we call the im- 
pression an interpretation of personality. 
With fuller acquaintance each person grad- 
ually assumes an individuality of his own, a 
personality of his own. 

Historically, the word originated from the 
Latin term "persona," meaning a mask, which 
was worn by an actor in a play. Later the 
"dramatis personae" were the characters in 
the play. Each actor was distinguished by his 



202 THE AVIATOR 

"persona." Thus the term comes to indicate, 
as the Standard Dictionary states, "the attri- 
butes taken collectively, that make up the 
character and nature of an individual; that 
which distinguishes and characterizes a per- 
son." 

What these components are that enter into 
the making of a personality is still a debated 
question. The ancients ascribed four tem- 
peraments to mankind; and sought to find a 
physical basis for them. The same effort 
reaches to our day and various physical char- 
acteristics are found to account for differences 
of personality. One interesting attempt is the 
tracing out the similarities in character and 
tastes of identical twins. Here we have ex- 
actly the same heredity, and the physical 
features are astonishingly alike. The whorls 
in the skin of the finger tips are of the same 
pattern ; in the few cases-studied the configura- 
tions of the brain and the bundles of muscles 
are strikingly similar. In many instances the 
likes and dislikes, the mental ability, are as 



PILOT AS A PERSONALITY 203 

similar as size, weight, and expression. Such 
studies stress the physical basis of personality. 
So, too, -do many investigations into altered 
personality. Cases are to be found in every 
state hospital of changed personality due to 
disease. An ambitious attempt has been made 
to interpret the personality of famous men in 
terms of physical characteristics. An ex- 
ample .might be cited to illustrate this kind of 
theory. Carlyle and Stevenson were both 
Scotch authors. Something of the Scotch 
temperament may be found in the writings of 
each, but Carlyle is characterized by a melan- 
choly and pessimism while Stevenson is spark- 
ling with a wholesome optimism. Carlyle 
was suffering from an intestinal disorder 
which invariably makes for melancholy. 
Stevenson was dying with pulmonary tuber- 
culosis which brings into the constitution a 
toxin that affects the nervous system in a char- 
acteristic way. It gives a peculiar sense of 
well-being and an attitude of cheerfulness 
toward life. 



2o 4 THE AVIATOR 

Illustrations of this sort are rather spec- 
tacular and may be challenged, but the idea 
involved is an old one; namely, that changes 
in the physical constitution bring about 
changes in one's moods, feelings, ideas and 
temperament. So well grounded is this prin- 
ciple that it is not uncommon to find medical 
men assuming that the whole of one's person- 
ality is a matter of heredity and development 
of the physical organs, especially the glands of 
internal secretion. However, the experience 
of every observant man leads him to the con- 
viction that there is something more enter- 
ing into the making of his personality. In- 
cidents occur in everyone's life which affect 
the habits of thinking and acting. Friend- 
ships often alter the personal habits of a young 
man. The association with men of excep- 
tional character, or genius, makes a youth take 
on some of the traits of the stronger and more 
mature nature. Education is based on the 
principle that human nature is plastic, and 
not only the intelligence, but the character 



PILOT AS A PERSONALITY 205 

may be fashioned according to set plans. It 
is a common remark in English educational 
circles that men coming up to Oxford, or 
Cambridge, can be identified very easily with 
certain historic schools such as Eton, or Har- 
row, where they prepared. These historic 
schools develop definite types of men. Our 
West Point men are trained to work hard and 
to stick to a problem until they have worked 
their way through it. They are disciplined 
in stating their results clearly and definitely, 
regardless of anything but the facts stated. 
Such practices develop mental habits and 
moral character as well. Truthfulness is a 
habit of men trained in this way. 

All sorts of modifications of one's inherited 
traits may be brought about by direct educa- 
tion and by indirect influences. Teachers 
frequently impart more by way of their per- 
sonal characteristics than through their care- 
ful instructions. In aviation this was often 
illustrated. Instructors who had confidence 
in themselves unconsciously inspired their 



2o6 THE AVIATOR 

pupils with confidence. Men who were me- 
thodical and careful in their inspection of the 
airplane before going up, and who systematic- 
ally conformed to the flying rules of the field, 
had no difficulty in obtaining an unconscious 
imitation on the part of their students. More 
subtle traits were also contagious. Clean- 
minded men, real sportsmen, gentlemen by 
birth and breeding had a definite influence 
upon the young cadets who were being trained 
by them. Several cadets, who had always 
lived in rather restricted environments, con- 
fided to me that the best thing they had ob- 
tained from their flying instruction was the 
association with a class of men whom they had 
never met before. Unfortunately, there were 
instructors who prided themselves on being 
rough, "hard boiled" types. I remember the 
reaction of one cadet to such a man. His in- 
structor cursed him thoroughly on the ground 
and in the air for any little awkwardness he 
showed. During one flight the cadet's pa- 
tience gave way and he arose, turned around, 



PILOT AS A PERSONALITY 207 

shook his fist at his teacher and cursed him, 
with a complete indifference to the airplane, 
the army regulations, and the English gram- 
mar. Such occurrences were not frequent, at 
least in my observations. The type of instruc- 
tor was usually one which the student re- 
spected. 

How quickly the contagion of personal in- 
fluences spreads finds many examples in the 
change of .morale in the different flying fields. 
Indeed, the tension upon the men learning to 
fly is so great that they seem more susceptible 
to such influences than men in ordinary life. 
It was a practice in many English fields, and 
in ours also, to send a man away on leave when 
he had gone stale and had lost his confidence, 
or become moody and apprehensive. Such 
a man was 'a focus of infection. His mood 
became contagious. He had lost his value for 
the service temporarily and was pulling others 
down with him. On the other hand, I have 
seen the morale of a group of men change 
definitely for the better when a commanding 



208 THE AVIATOR 

officer, whom they barely respected, was sup- 
planted by one who immediately gave evi- 
dence of efficiency and ability. 

Surround young men, who are still in the 
formative period of life, with an environment 
and a set of influences of a consistent and con- 
tinuous character and inevitably the result is 
a moulding of their personalities to a given 
pattern. Naturally, there are as many devia- 
tions from the pattern as there are men, but 
something of the type sought will be detectable 
in the majority of the men, Each man has 
his peculiar heritage and physical constitution 
and the same treatment cannot give exactly the 
same results. Nevertheless, habits may be 
built up which give their thinking and their 
conduct definite trends. And, in the last 
analysis, habit is a second nature, so it is prac- 
ticable to direct this portion of a man's nature 
according to specifications. 

In aviation, the requirements in personality 
are numerous. Among the most necessary we 
might mention the following: First, confi- 



PILOT AS A PERSONALITY 209 

dence in oneself is a primary requisite. This 
is recognized now, as it was not in the begin- 
ning of the war. Confidence, with men of any 
intelligence, comes with the mastery of an art 
or a sport. Frequent mistakes and corrections 
undermine anyone's confidence, unless he has 
an abnormal conceit. To avoid such an at- 
titude of apprehension, the more recent train- 
ing keeps a man in dual flights until he knows 
how to do a number of stunts and acquires the 
confidence that he can pull his ship out of any 
position she might happen to take. With a 
knowledge of what can happen and what to 
do when it does happen, a man feels fortified. 
Some men are endowed with a natural assur- 
ance and a native trust in their own abilities, 
others have to acquire that habit of self- 
reliance. It is nothing more than a habit! 
Nothing furnishes a better training in this 
feature of character formation than aviation. 
With great satisfaction, several men who had 
just won their wings told me that the dis- 
cipline they had received in self-reliance was 



2io THE AVIATOR 

invaluable. They felt that it was a perma- 
nent acquisition, and one that would genuinely 
aid them in after life. 

Somewhat similar to confidence in one's 
ability to take care of himself is a certain 
sense of self-sufficiency. A man who is alone 
in the air for hours at a time is the most lone- 
some creature imaginable. His thoughts may 
take any direction. He may become morbid 
and disgusted with his work and himself. If 
he happens to think out the situation, he finds 
that he must control his thoughts and direct 
them in a wholefsome way. Once accom- 
plished, this habit of shaping one's inner life 
of ideas becomes a very valuable asset to any 
man's personality. It is a question whether 
the imaginative type of mind is an advantage 
or not. One of my acquaintances collided 
with an airplane as he flew out of a cloud. 
He was in the hospital for months. When 
he was able, he took up his flying work as 
usual. The accident had not damaged his 
confidence at all, except that he was a little 



PILOT AS A PERSONALITY 211 

anxious when he approached another airplane 
in flight. He was a most unimaginative type. 
He had failed in college for this very reason 
— so he said. His explanation of the fact that 
the accident had not affected him was this, "I 
never think!" Perhaps he was lucky. At all 
events, if one does think, and is inclined to 
remember unpleasant incidents, he must learn 
what routes his ideas take and compel them 
to go the way that makes for mental health. 

One of the besetting sins of education is the 
habit of hesitancy in thinking. Occasionally, 
a college graduate will remark that the habit 
of thinking around a subject has ruined him, 
for he cannot come to a decision. When this 
misfortune spreads to the ability for thinking 
and acting promptly, there is a bad bill to 
pay. Indecision is fatal in aviation. Here, 
too, the personality can be reshaped by the 
formation of the habit of acting on the spur 
of the moment and of sticking to the course 
adopted. It is a habit the flier must form. 
With its development comes a certain stabil- 



212 THE AVIATOR 

ity of character, for nothing is more demoral- 
izing than indecision. Aviation furnishes a 
splendid antidote for the youth in whom "the 
native hue of resolution is sicklied o'er with 
a pale cast of thought." 

Nor may the aviator yield to another seduc- 
tive habit, that of making a wish the father 
to a thought It is well enough to wish the 
life belt were strong enough to hold, or that 
the spark plugs are clean enough for a flight, 
but it is desperately bad practice to let the 
desire make the assumption. Aviation is an 
exact science. Things must be faced as they 
are. No chances can be taken on the basis of 
a hope. The man who is in a hurry, or who 
is lazy and is willing to take a chance on the 
ship's being in fit condition to fly has the 
wrong attitude toward his art. If this be- 
comes a habit his hope of longevity is futile. 

This carefree type of man is frequently the 
one which gives the reckless dare-devil, who 
is so useful in combat work. Young fellows 
in their early twenties are believed to be the 



PILOT AS A PERSONALITY 213 

best type; though I have heard many denials 
of this. Of course, it is hard to develop a 
personality which will take no chances on a 
faulty machine but which will take any 
chance in an unexpected flight. However, 
this very type did evolve during the war. 
Nothing could be finer. In such men all of 
the vim of youth unites with the good judg- 
ment of maturity. They were cautious where 
caution could win and took desperate chances 
w r here caution was out of the question. 
Again, this accomplishment is one of habit! 
True, it is a most difficult one to develop ; im- 
possible, perhaps, in some natures. When it 
has been worked into one's way of thinking 
and of managing his conduct it makes a very 
vigorous and virile personality. 

In peace times the work of the aviator may 
be adapted in some measure to his personal 
aptitudes. To some the mail carrying or pas- 
senger work makes an appeal, to others a more 
varied occupation is desirable, such as coast 
surveying, mapping, fire patrolling of forests, 



2i 4 THE AVIATOR 

experimenting with new designs in airplanes, 
or altitude and meteorological work. In any 
line of this new and diversified calling, there 
is a demand for at least one well-defined char- 
acteristic. It is the spirit of the pioneer. 
There must be a love of adventure — the old 
spirit of the Viking and the frontiersman. 
No man can hope to succeed in aviation who 
does not feel the impulse to explore, to win 
new experiences, to taste and enjoy untried 
dangers. Such an impulse is deep in our 
racial natures. Few men lack it entirely: al- 
most any man can awaken it, provided he has 
not lost his youth completely. 

Aviation, then, demands certain traits in a 
man's personality. Moreover, it tends to de- 
velop these traits as a man becomes really pro- 
ficient. As a means of selecting men of a 
certain type it is valuable and as a means 
of educating and producing such men it is still 
more valuable. It is not too much to claim 
that this type of man is one of the nation's 
best assets. 



